diff --git a/be2-scala/src/main/scala/ch/epfl/pop/Server.scala b/be2-scala/src/main/scala/ch/epfl/pop/Server.scala
index 8962d90a09..677b02e93d 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/Server.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/Server.scala
@@ -7,7 +7,7 @@ import akka.actor.{ActorRef, Props}
 import akka.http.scaladsl.Http
 import akka.http.scaladsl.server.Directives._
 import akka.http.scaladsl.server.{RequestContext, RouteResult}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.util.Timeout
 import ch.epfl.pop.config.{RuntimeEnvironment, ServerConf}
 import ch.epfl.pop.pubsub.{MessageRegistry, PubSubMediator, PublishSubscribe}
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/json/HighLevelProtocol.scala b/be2-scala/src/main/scala/ch/epfl/pop/json/HighLevelProtocol.scala
index b714b5efe6..05d70f7405 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/json/HighLevelProtocol.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/json/HighLevelProtocol.scala
@@ -84,13 +84,13 @@ object HighLevelProtocol extends DefaultJsonProtocol {
       Broadcast(params.channel, params.message)
     }
 
-    override def write(obj: Broadcast): JsValue = obj.toJson(ParamsFormat.write)
+    override def write(obj: Broadcast): JsValue = obj.toJson(ParamsFormat.write _)
   }
 
   implicit object CatchupFormat extends RootJsonFormat[Catchup] {
     override def read(json: JsValue): Catchup = Catchup(json.convertTo[Params].channel)
 
-    override def write(obj: Catchup): JsValue = obj.toJson(ParamsFormat.write)
+    override def write(obj: Catchup): JsValue = obj.toJson(ParamsFormat.write _)
   }
 
   implicit object PublishFormat extends RootJsonFormat[Publish] {
@@ -99,19 +99,19 @@ object HighLevelProtocol extends DefaultJsonProtocol {
       Publish(params.channel, params.message)
     }
 
-    override def write(obj: Publish): JsValue = obj.toJson(ParamsFormat.write)
+    override def write(obj: Publish): JsValue = obj.toJson(ParamsFormat.write _)
   }
 
   implicit object SubscribeFormat extends RootJsonFormat[Subscribe] {
     override def read(json: JsValue): Subscribe = Subscribe(json.convertTo[Params].channel)
 
-    override def write(obj: Subscribe): JsValue = obj.toJson(ParamsFormat.write)
+    override def write(obj: Subscribe): JsValue = obj.toJson(ParamsFormat.write _)
   }
 
   implicit object UnsubscribeFormat extends RootJsonFormat[Unsubscribe] {
     override def read(json: JsValue): Unsubscribe = Unsubscribe(json.convertTo[Params].channel)
 
-    override def write(obj: Unsubscribe): JsValue = obj.toJson(ParamsFormat.write)
+    override def write(obj: Unsubscribe): JsValue = obj.toJson(ParamsFormat.write _)
   }
 
 
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/model/objects/ElectionChannel.scala b/be2-scala/src/main/scala/ch/epfl/pop/model/objects/ElectionChannel.scala
index 8b2f3d8ff1..ce5c4cbc56 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/model/objects/ElectionChannel.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/model/objects/ElectionChannel.scala
@@ -20,7 +20,7 @@ object ElectionChannel {
      * @tparam T type of data to extract from the election channel
      * @return Future of a list of tuple containing the message and the data extracted
      */
-    def extractMessages[T: Manifest](dbActor: AskableActorRef = DbActor.getInstance): Future[List[(Message, T)]] = {
+    def extractMessages[T: reflect.ClassTag](dbActor: AskableActorRef = DbActor.getInstance): Future[List[(Message, T)]] = {
       for {
         DbActor.DbActorCatchupAck(messages) <- dbActor ? DbActor.Catchup(channel)
         result <- Future.traverse(messages.flatMap(message =>
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/ClientActor.scala b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/ClientActor.scala
index a8fbc7f666..94f3417022 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/ClientActor.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/ClientActor.scala
@@ -2,7 +2,7 @@ package ch.epfl.pop.pubsub
 
 import akka.actor.{Actor, ActorLogging, ActorRef, Props}
 import akka.event.LoggingReceive
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import ch.epfl.pop.model.objects.Channel
 import ch.epfl.pop.pubsub.ClientActor._
 import ch.epfl.pop.pubsub.PubSubMediator._
@@ -93,7 +93,7 @@ object ClientActor {
   final case class ConnectWsHandle(wsClient: ActorRef) extends Event
 
   // unsubscribe from all channels
-  final case object DisconnectWsHandle extends Event
+  case object DisconnectWsHandle extends Event
 
   // subscribe to a particular channel
   final case class SubscribeTo(channel: Channel) extends Event
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/Answerer.scala b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/Answerer.scala
index 5ea8ade042..c44a9080fe 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/Answerer.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/Answerer.scala
@@ -45,7 +45,7 @@ object Answerer {
       // Send the ClientAnswer to clientActorRef. Whenever the stream between the client
       // actor and the actual client (front-end) is broken, the message DisconnectWsHandle
       // is sent to clientActorRef
-      .to(Sink.actorRef(clientActorRef, DisconnectWsHandle, { t: Throwable => println(t); DisconnectWsHandle }))
+      .to(Sink.actorRef(clientActorRef, DisconnectWsHandle, { (t: Throwable) => println(t); DisconnectWsHandle }))
 
     // Integration point between Akka Streams and above actor
     val source: Source[TextMessage, NotUsed] = Source
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/LaoHandler.scala b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/LaoHandler.scala
index 16d4ab43f0..96971700f2 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/LaoHandler.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/LaoHandler.scala
@@ -54,7 +54,7 @@ case object LaoHandler extends MessageHandler {
           _ <- dbActor ? DbActor.WriteLaoData(laoChannel, message, address)
           //after creating the lao, we need to send a lao#greet message to the frontend
           greet: GreetLao = GreetLao(data.id, params.get.sender, address.get, List.empty)
-          broadcastGreet: Base64Data = Base64Data.encode(GreetLaoFormat.write(greet).toString())
+          broadcastGreet: Base64Data = Base64Data.encode(GreetLaoFormat.write(greet).toString)
           _ <- dbBroadcast(rpcMessage, laoChannel, broadcastGreet, laoChannel)
         } yield ()
 
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/ParamsHandler.scala b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/ParamsHandler.scala
index f54ffac40b..3fd3ac44e1 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/ParamsHandler.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/ParamsHandler.scala
@@ -2,7 +2,7 @@ package ch.epfl.pop.pubsub.graph.handlers
 
 import akka.NotUsed
 import akka.actor.ActorRef
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.stream.FlowShape
 import akka.stream.scaladsl.{Flow, GraphDSL, Merge, Partition}
 import ch.epfl.pop.model.network.method.{Catchup, Subscribe, Unsubscribe}
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandler.scala b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandler.scala
index b2601ea98c..2c8dc9893c 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandler.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandler.scala
@@ -174,7 +174,7 @@ class RollCallHandler(dbRef: => AskableActorRef) extends MessageHandler {
           ))
         }
       case error@Right(_) => error
-      case _ => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, unknownAnswer, rpcRequest.id))
+      case null => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, unknownAnswer, rpcRequest.id))
     }
   }
 
diff --git a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandler.scala b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandler.scala
index 1434ff17ed..a91c10eae8 100644
--- a/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandler.scala
+++ b/be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandler.scala
@@ -58,7 +58,7 @@ class SocialMediaHandler(dbRef: => AskableActorRef) extends MessageHandler {
           case None => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, "Server failed to extract LAO id for the broadcast", rpcMessage.id))
         }
       case error@Right(_) => error
-      case _ => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, unknownAnswerDatabase, rpcMessage.id))
+      case null => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, unknownAnswerDatabase, rpcMessage.id))
     }
   }
 
@@ -81,7 +81,7 @@ class SocialMediaHandler(dbRef: => AskableActorRef) extends MessageHandler {
           case None => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, "Server failed to extract LAO id for the broadcast", rpcMessage.id))
         }
       case error@Right(_) => error
-      case _ => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, unknownAnswerDatabase, rpcMessage.id))
+      case null => Right(PipelineError(ErrorCodes.SERVER_ERROR.id, unknownAnswerDatabase, rpcMessage.id))
     }
   }
 
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/model/objects/ChannelSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/model/objects/ChannelSuite.scala
index edbd307ea3..b34b88574a 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/model/objects/ChannelSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/model/objects/ChannelSuite.scala
@@ -64,7 +64,6 @@ class ChannelSuite extends AnyFunSuite with should.Matchers {
     def channel = Channel("/root/full/pop")
 
     val expected = Hash(Base64Data("pop"))
-    an[IllegalArgumentException] shouldNot be(thrownBy(channel))
     channel.extractChildChannel should equal(expected)
   }
   test("Encoded LaoId extraction channel test") {
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/AnswerGeneratorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/AnswerGeneratorSuite.scala
index ab4e38236e..77d453ea10 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/AnswerGeneratorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/AnswerGeneratorSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph
 
 import akka.actor.{Actor, ActorSystem, Props, Status}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.model.network.method.message.Message
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/ElectionHandlerTest.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/ElectionHandlerTest.scala
index 86095fc635..fa216bf9d0 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/ElectionHandlerTest.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/ElectionHandlerTest.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.handlers
 
 import akka.actor.{Actor, ActorSystem, Props, Status}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.model.network.method.message.Message
@@ -36,12 +36,12 @@ class ElectionHandlerTest extends TestKit(ActorSystem("Election-DB-System")) wit
   private val keyPair: KeyPair = KeyPair()
   private val electionData: ElectionData = ElectionData(Hash(Base64Data.encode("election")), keyPair)
 
-  private final val sender: PublicKey = SetupElectionExamples.SENDER_SETUPELECTION
+  private final val SENDER: PublicKey = SetupElectionExamples.SENDER_SETUPELECTION
 
   private final val PUBLIC_KEY: PublicKey = PublicKey(Base64Data("jsNj23IHALvppqV1xQfP71_3IyAHzivxiCz236_zzQc="))
   private final val PRIVATE_KEY: PrivateKey = PrivateKey(Base64Data("qRfms3wzSLkxAeBz6UtwA-L1qP0h8D9XI1FSvY68t7Y="))
   private final val PK_OWNER: PublicKey = PublicKey(Base64Data.encode("wrongOwner"))
-  private final val laoDataRight: LaoData = LaoData(sender, List(sender), PRIVATE_KEY, PUBLIC_KEY, List.empty)
+  private final val laoDataRight: LaoData = LaoData(SENDER, List(SENDER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
 
   private final val channelDataWithSetupAndOpenAndCastMessage: ChannelData = ChannelData(ObjectType.ELECTION, List(DATA_CAST_VOTE_MESSAGE, DATA_SET_UP_OPEN_BALLOT, DATA_OPEN_MESSAGE))
   private final val messages: List[Message] = List(MESSAGE_CAST_VOTE_ELECTION_WORKING, MESSAGE_SETUPELECTION_OPEN_BALLOT_WORKING, MESSAGE_OPEN_ELECTION_WORKING, MESSAGE_END_ELECTION_WORKING)
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandlerTest.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandlerTest.scala
index ad8757578b..cb1d1b63af 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandlerTest.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/RollCallHandlerTest.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.handlers
 
 import akka.actor.{Actor, ActorSystem, Props, Status}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.model.objects.DbActorNAckException
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandlerSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandlerSuite.scala
index c88bfff911..e71d0b6af0 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandlerSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/handlers/SocialMediaHandlerSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.handlers
 
 import akka.actor.{Actor, ActorSystem, Props, Status}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.model.objects.DbActorNAckException
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/ElectionValidatorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/ElectionValidatorSuite.scala
index 4ca5ed7801..88ef5b02c0 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/ElectionValidatorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/ElectionValidatorSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.validators
 
 import akka.actor.{Actor, ActorRef, ActorSystem, Props}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.config.RuntimeEnvironment.deleteRecursively
@@ -46,12 +46,12 @@ class ElectionValidatorSuite extends TestKit(ActorSystem("electionValidatorTestA
     deleteRecursively(directory)
   }
 
-  private final val sender: PublicKey = SetupElectionExamples.SENDER_SETUPELECTION
+  private final val SENDER: PublicKey = SetupElectionExamples.SENDER_SETUPELECTION
 
   private final val PUBLIC_KEY: PublicKey = PublicKey(Base64Data("jsNj23IHALvppqV1xQfP71_3IyAHzivxiCz236_zzQc="))
   private final val PRIVATE_KEY: PrivateKey = PrivateKey(Base64Data("qRfms3wzSLkxAeBz6UtwA-L1qP0h8D9XI1FSvY68t7Y="))
   private final val PK_WRONG: PublicKey = PublicKey(Base64Data.encode("wrongOwner"))
-  private final val laoDataRight: LaoData = LaoData(sender, List(sender), PRIVATE_KEY, PUBLIC_KEY, List.empty)
+  private final val laoDataRight: LaoData = LaoData(SENDER, List(SENDER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
   private final val laoDataWrong: LaoData = LaoData(PK_WRONG, List(PK_WRONG), PRIVATE_KEY, PUBLIC_KEY, List.empty)
   private final val channelDataRightSetup: ChannelData = ChannelData(ObjectType.LAO, List.empty)
   private final val channelDataWrongSetup: ChannelData = ChannelData(ObjectType.ELECTION, List.empty)
@@ -433,7 +433,7 @@ class ElectionValidatorSuite extends TestKit(ActorSystem("electionValidatorTestA
   test("Open up an election with invalid lao id fails") {
     val dbActorRef = mockDbWorking
     val message: GraphMessage = new ElectionValidator(dbActorRef).validateOpenElection(OPEN_ELECTION_WRONG_LAO_ID_RPC)
-   val messageStandardActor: GraphMessage = ElectionValidator.validateOpenElection(OPEN_ELECTION_WRONG_LAO_ID_RPC)
+    val messageStandardActor: GraphMessage = ElectionValidator.validateOpenElection(OPEN_ELECTION_WRONG_LAO_ID_RPC)
     message shouldBe a[Right[_, PipelineError]]
     messageStandardActor shouldBe a[Right[_, PipelineError]]
     system.stop(dbActorRef.actorRef)
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/LaoValidatorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/LaoValidatorSuite.scala
index 4e75e74ce5..a4ce7ebc86 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/LaoValidatorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/LaoValidatorSuite.scala
@@ -5,7 +5,7 @@ import ch.epfl.pop.config.RuntimeEnvironment.deleteRecursively
 import ch.epfl.pop.model.network.method.message.data.ObjectType
 import ch.epfl.pop.model.objects.{Base64Data, ChannelData, LaoData, PrivateKey, PublicKey}
 import ch.epfl.pop.storage.{DbActor, InMemoryStorage}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.pubsub.graph.{GraphMessage, PipelineError}
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MeetingValidatorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MeetingValidatorSuite.scala
index 0f75497e7d..1fbdba81a5 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MeetingValidatorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MeetingValidatorSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.validators
 
 import akka.actor.{Actor, ActorRef, ActorSystem, Props}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.config.RuntimeEnvironment.deleteRecursively
@@ -46,12 +46,12 @@ class MertingValidatorSuite extends TestKit(ActorSystem("meetingValidatorTestAct
     deleteRecursively(directory)
   }
 
-  private final val sender: PublicKey = PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM="))
+  private final val SENDER: PublicKey = PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM="))
 
   private final val PUBLIC_KEY: PublicKey = PublicKey(Base64Data("jsNj23IHALvppqV1xQfP71_3IyAHzivxiCz236_zzQc="))
   private final val PRIVATE_KEY: PrivateKey = PrivateKey(Base64Data("qRfms3wzSLkxAeBz6UtwA-L1qP0h8D9XI1FSvY68t7Y="))
   private final val PK_OWNER: PublicKey = PublicKey(Base64Data.encode("wrongOwner"))
-  private final val laoDataRight: LaoData = LaoData(sender, List(sender), PRIVATE_KEY, PUBLIC_KEY, List.empty)
+  private final val laoDataRight: LaoData = LaoData(SENDER, List(SENDER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
   private final val laoDataWrong: LaoData = LaoData(PK_OWNER, List(PK_OWNER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
   private final val channelDataRightSetup: ChannelData = ChannelData(ObjectType.LAO, List.empty)
   private final val channelDataWrongSetup: ChannelData = ChannelData(ObjectType.ELECTION, List.empty)
@@ -255,4 +255,4 @@ class MertingValidatorSuite extends TestKit(ActorSystem("meetingValidatorTestAct
     messageStandardActor shouldBe a[Right[_, PipelineError]]
     system.stop(dbActorRef.actorRef)
   }
-}
\ No newline at end of file
+}
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MessageValidatorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MessageValidatorSuite.scala
index dccd9a3086..15b367a4d0 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MessageValidatorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/MessageValidatorSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.validators
 
 import akka.actor.{Actor, ActorSystem, Props, Status}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.model.network.method.message.data.ObjectType
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/RollCallValidatorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/RollCallValidatorSuite.scala
index c5ff644635..19b1d05913 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/RollCallValidatorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/RollCallValidatorSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.pubsub.graph.validators
 
 import akka.actor.{Actor, ActorRef, ActorSystem, Props}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.config.RuntimeEnvironment.deleteRecursively
@@ -46,13 +46,11 @@ class RollCallValidatorSuite extends TestKit(ActorSystem("rollcallValidatorTestA
     deleteRecursively(directory)
   }
 
-  private final val sender: PublicKey = SENDER
-
   private final val PUBLIC_KEY: PublicKey = PublicKey(Base64Data("jsNj23IHALvppqV1xQfP71_3IyAHzivxiCz236_zzQc="))
   private final val PRIVATE_KEY: PrivateKey = PrivateKey(Base64Data("qRfms3wzSLkxAeBz6UtwA-L1qP0h8D9XI1FSvY68t7Y="))
   private final val PK_OWNER: PublicKey = PublicKey(Base64Data.encode("wrongOwner"))
-  private final val laoDataRight: LaoData = LaoData(sender, List(sender), PRIVATE_KEY, PUBLIC_KEY, List.empty)
-  private final val laoDataWrong: LaoData = LaoData(sender, List(PK_OWNER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
+  private final val laoDataRight: LaoData = LaoData(SENDER, List(SENDER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
+  private final val laoDataWrong: LaoData = LaoData(SENDER, List(PK_OWNER), PRIVATE_KEY, PUBLIC_KEY, List.empty)
   private final val channelDataWrong: ChannelData = ChannelData(ObjectType.INVALID, List.empty)
   private final val channelDataRight: ChannelData = ChannelData(ObjectType.LAO, List.empty)
   private final val rollcallDataCreate: RollCallData = RollCallData(CreateRollCallExamples.R_ID, ActionType.CREATE)
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/SocialMediaValidatorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/SocialMediaValidatorSuite.scala
index 5f13364815..9dc053fb6f 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/SocialMediaValidatorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/pubsub/graph/validators/SocialMediaValidatorSuite.scala
@@ -4,7 +4,7 @@ import java.io.File
 import java.util.concurrent.TimeUnit
 
 import akka.actor.{Actor, ActorRef, ActorSystem, Props}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import akka.util.Timeout
 import ch.epfl.pop.config.RuntimeEnvironment.deleteRecursively
diff --git a/be2-scala/src/test/scala/ch/epfl/pop/storage/DbActorSuite.scala b/be2-scala/src/test/scala/ch/epfl/pop/storage/DbActorSuite.scala
index 936d9a409b..3292c8ae44 100644
--- a/be2-scala/src/test/scala/ch/epfl/pop/storage/DbActorSuite.scala
+++ b/be2-scala/src/test/scala/ch/epfl/pop/storage/DbActorSuite.scala
@@ -1,7 +1,7 @@
 package ch.epfl.pop.storage
 
 import akka.actor.{ActorRef, ActorSystem, Props}
-import akka.pattern.AskableActorRef
+import akka.pattern.{AskableActorRef, ask}
 import akka.testkit.{ImplicitSender, TestKit}
 import ch.epfl.pop.model.network.method.message.Message
 import ch.epfl.pop.model.network.method.message.data.ActionType.{ActionType, CREATE}
diff --git a/be2-scala/src/test/scala/util/examples/MessageExample.scala b/be2-scala/src/test/scala/util/examples/MessageExample.scala
index 95d040f41a..117229b169 100644
--- a/be2-scala/src/test/scala/util/examples/MessageExample.scala
+++ b/be2-scala/src/test/scala/util/examples/MessageExample.scala
@@ -179,7 +179,7 @@ object MessageExample {
   final val HASH_MEETING_OBJECT: Hash = Hash.fromStrings("M", laoIdMEeeting, ""+creationMeeting, nameMeeting)
   final val mettingCreate: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None)
   final val MESSAGE_CREATE_MEETING: Message = new Message(
-    Base64Data.encode(mettingCreate.toJson.toString()),
+    Base64Data.encode(mettingCreate.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -191,7 +191,7 @@ object MessageExample {
   final val HASH_MEETING_OBJECT_WRONG_CHANNEL: Hash = Hash.fromStrings("M", laoIdMeetingWrongChannel, ""+creationMeeting, nameMeeting)
   final val mettingCreateWrongChannel: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None)
   final val MESSAGE_CREATE_MEETING_WRONG_CHANNEL: Message = new Message(
-    Base64Data.encode(mettingCreateWrongChannel.toJson.toString()),
+    Base64Data.encode(mettingCreateWrongChannel.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -202,7 +202,7 @@ object MessageExample {
   final val HASH_MEETING_OBJECT_WRONG_DATA: Hash = Hash.fromStrings("M", laoIdMeetingWrongChannel, ""+creationMeeting, nameMeeting, "wrongElement")
   final val meetingCreateWrongData: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT_WRONG_DATA, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None)
   final val MESSAGE_CREATE_MEETING_WRONG_DATA: Message = new Message(
-    Base64Data.encode(meetingCreateWrongData.toJson.toString()),
+    Base64Data.encode(meetingCreateWrongData.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -214,7 +214,7 @@ object MessageExample {
   final val HASH_MEETING_OBJECT_STALE_CREATION: Hash = Hash.fromStrings("M", laoIdMEeeting, ""+creationMeetingSmall, nameMeeting)
   final val meetingCreateSmallCreation: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT_STALE_CREATION, nameMeeting, creationMeetingSmall, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None)
   final val MESSAGE_CREATE_MEETING_SMALL_CREATION: Message = new Message(
-    Base64Data.encode(meetingCreateSmallCreation.toJson.toString()),
+    Base64Data.encode(meetingCreateSmallCreation.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -224,7 +224,7 @@ object MessageExample {
 
   final val meetingCreateSmallStart: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(170), Some(Timestamp(1633102500)), None)
   final val MESSAGE_CREATE_MEETING_SMALL_START: Message = new Message(
-    Base64Data.encode(meetingCreateSmallStart.toJson.toString()),
+    Base64Data.encode(meetingCreateSmallStart.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -232,9 +232,9 @@ object MessageExample {
     Some(meetingCreateSmallStart)
   )
 
-final val meetingCreateInvalidEnd: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(1633098400), Some(Timestamp(1633098200)), None)
-final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
-    Base64Data.encode(meetingCreateInvalidEnd.toJson.toString()),
+  final val meetingCreateInvalidEnd: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(1633098400), Some(Timestamp(1633098200)), None)
+  final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
+    Base64Data.encode(meetingCreateInvalidEnd.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -244,7 +244,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val meetingCreateSmallEnd: CreateMeeting = CreateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Some("EPFL"),  Timestamp(1633102500), Some(Timestamp(1633102000)), None)
   final val MESSAGE_CREATE_MEETING_START_BIGGER_THAN_END: Message = new Message(
-    Base64Data.encode(meetingCreateSmallEnd.toJson.toString()),
+    Base64Data.encode(meetingCreateSmallEnd.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -257,7 +257,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
   final val witnessSignatures: List[WitnessSignaturePair] = List.empty
   final val validStateMeeting: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING: Message = new Message(
-    Base64Data.encode(validStateMeeting.toJson.toString()),
+    Base64Data.encode(validStateMeeting.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -267,7 +267,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val invalidStateMeetingWrongData: StateMeeting = StateMeeting(HASH_MEETING_OBJECT_WRONG_DATA, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING_INVALID_DATA: Message = new Message(
-    Base64Data.encode(invalidStateMeetingWrongData.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingWrongData.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -277,7 +277,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val invalidStateMeetingStaleCreationTime: StateMeeting = StateMeeting(HASH_MEETING_OBJECT_STALE_CREATION, nameMeeting, Timestamp(123), lastModified, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING_INVALID_CREATION: Message = new Message(
-    Base64Data.encode(invalidStateMeetingStaleCreationTime.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingStaleCreationTime.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -287,7 +287,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val invalidStateMeetingStaleStartTime: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(163), Some(Timestamp(1633102500)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING_INVALID_START: Message = new Message(
-    Base64Data.encode(invalidStateMeetingStaleStartTime.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingStaleStartTime.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -297,7 +297,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val invalidStateMeetingSmallStartTime: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(1633098300), Some(Timestamp(1633102500)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING_SMALL_START: Message = new Message(
-    Base64Data.encode(invalidStateMeetingSmallStartTime.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingSmallStartTime.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -307,7 +307,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val invalidStateMeetingSmallEndTime: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(1633098400), Some(Timestamp(1633098300)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING_SMALL_END: Message = new Message(
-    Base64Data.encode(invalidStateMeetingSmallEndTime.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingSmallEndTime.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -317,7 +317,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
 
   final val invalidStateMeetingSmallModificationTime: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, Timestamp(1633098300), Some("EPFL"),  Timestamp(1633098400), Some(Timestamp(1633098500)), None, modificationId, witnessSignatures)
   final val MESSAGE_STATE_MEETING_SMALL_MODIFICATION_TIME: Message = new Message(
-    Base64Data.encode(invalidStateMeetingSmallModificationTime.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingSmallModificationTime.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -327,7 +327,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
   
   final val invalidStateMeetingBigStartTime: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(1633102500), Some(Timestamp(1633098900)), None, modificationId, witnessSignatures)
   final val  MESSAGE_STATE_MEETING_BIG_START: Message = new Message(
-    Base64Data.encode(invalidStateMeetingBigStartTime.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingBigStartTime.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),
@@ -338,7 +338,7 @@ final val MESSAGE_CREATE_MEETING_SMALL_END: Message = new Message(
   final val invalidWitnessSignatures: List[WitnessSignaturePair] = WitnessSignaturePair.apply(PublicKey(Base64Data("M5ZychEi5rwm22FjwjNuljL1qMJWD2sE7oX9fcHNMDU=")), Signature(Base64Data("XXX"))) :: List.empty
   final val invalidStateMeetingWrongWitnessSignature: StateMeeting = StateMeeting(HASH_MEETING_OBJECT, nameMeeting, creationMeeting, lastModified, Some("EPFL"),  Timestamp(1633098900), Some(Timestamp(1633102500)), None, modificationId, invalidWitnessSignatures)
   final val MESSAGE_STATE_MEETING_WRONG_WITNESS_SIGNATURE: Message = new Message(
-    Base64Data.encode(invalidStateMeetingWrongWitnessSignature.toJson.toString()),
+    Base64Data.encode(invalidStateMeetingWrongWitnessSignature.toJson.toString),
     PublicKey(Base64Data("J9fBzJV70Jk5c-i3277Uq4CmeL4t53WDfUghaK0HpeM=")),
     Signature(Base64Data("")),
     Hash(Base64Data("")),