diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/executor/InstrumentationProcessRunner.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/executor/InstrumentationProcessRunner.kt
index 9a2b7572a2..a7332a0815 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/executor/InstrumentationProcessRunner.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/executor/InstrumentationProcessRunner.kt
@@ -11,7 +11,8 @@ import org.usvm.instrumentation.rd.InstrumentedProcess
 import org.usvm.instrumentation.testcase.UTest
 import org.usvm.instrumentation.testcase.api.UTestExecutionResult
 import org.usvm.instrumentation.util.InstrumentationModuleConstants
-import osSpecificJavaExecutable
+import org.usvm.instrumentation.util.OpenModulesContainer
+import org.usvm.instrumentation.util.osSpecificJavaExecutable
 import java.io.File
 import java.nio.file.Paths
 import kotlin.reflect.KClass
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/JcRuntimeTraceInstrumenter.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/JcRuntimeTraceInstrumenter.kt
index b54622d4f2..a0c812d867 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/JcRuntimeTraceInstrumenter.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/JcRuntimeTraceInstrumenter.kt
@@ -9,7 +9,6 @@ import org.objectweb.asm.tree.ClassNode
 import org.objectweb.asm.tree.MethodNode
 import org.usvm.instrumentation.collector.trace.TraceCollector
 import org.usvm.instrumentation.instrumentation.JcInstructionTracer.StaticFieldAccessType
-import org.usvm.instrumentation.org.usvm.instrumentation.instrumentation.TraceHelper
 import org.usvm.instrumentation.util.isSameSignature
 import org.usvm.instrumentation.util.replace
 
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/TraceHelper.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/TraceHelper.kt
index 9ba3dab54a..532ee7ccc7 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/TraceHelper.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/TraceHelper.kt
@@ -1,4 +1,4 @@
-package org.usvm.instrumentation.org.usvm.instrumentation.instrumentation
+package org.usvm.instrumentation.instrumentation
 
 import org.jacodb.api.JcClasspath
 import org.jacodb.api.cfg.JcRawCallInst
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockClassRebuilder.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockClassRebuilder.kt
index 6b5ff16992..366f2c2eda 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockClassRebuilder.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockClassRebuilder.kt
@@ -1,4 +1,4 @@
-package org.usvm.instrumentation.org.usvm.instrumentation.mock
+package org.usvm.instrumentation.mock
 
 import org.jacodb.api.JcClassOrInterface
 import org.jacodb.api.JcMethod
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockHelper.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockHelper.kt
index 13c19ccbf7..76f43ad6d6 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockHelper.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/mock/MockHelper.kt
@@ -1,4 +1,4 @@
-package org.usvm.instrumentation.org.usvm.instrumentation.mock
+package org.usvm.instrumentation.mock
 
 import org.jacodb.api.*
 import org.jacodb.api.cfg.*
@@ -9,7 +9,7 @@ import org.objectweb.asm.tree.ClassNode
 import org.objectweb.asm.tree.MethodNode
 import org.usvm.instrumentation.classloader.WorkerClassLoader
 import org.usvm.instrumentation.instrumentation.JcInstructionTracer
-import org.usvm.instrumentation.org.usvm.instrumentation.instrumentation.TraceHelper
+import org.usvm.instrumentation.instrumentation.TraceHelper
 import org.usvm.instrumentation.collector.trace.MockCollector
 import org.jacodb.impl.cfg.*
 import org.usvm.instrumentation.util.*
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/rd/UTestExecutor.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/rd/UTestExecutor.kt
index 81502b4986..3cc95b184c 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/rd/UTestExecutor.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/rd/UTestExecutor.kt
@@ -8,7 +8,7 @@ import org.usvm.instrumentation.classloader.WorkerClassLoader
 import org.usvm.instrumentation.collector.trace.MockCollector
 import org.usvm.instrumentation.collector.trace.TraceCollector
 import org.usvm.instrumentation.instrumentation.JcInstructionTracer
-import org.usvm.instrumentation.org.usvm.instrumentation.mock.MockHelper
+import org.usvm.instrumentation.mock.MockHelper
 import org.usvm.instrumentation.testcase.UTest
 import org.usvm.instrumentation.testcase.api.*
 import org.usvm.instrumentation.testcase.descriptor.StaticDescriptorsBuilder
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/testcase/executor/UTestExpressionExecutor.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/testcase/executor/UTestExpressionExecutor.kt
index 2b8bb5d270..8be151d775 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/testcase/executor/UTestExpressionExecutor.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/testcase/executor/UTestExpressionExecutor.kt
@@ -6,7 +6,7 @@ import org.jacodb.api.JcField
 import org.jacodb.api.ext.*
 import org.usvm.instrumentation.classloader.WorkerClassLoader
 import org.usvm.instrumentation.instrumentation.JcInstructionTracer.StaticFieldAccessType
-import org.usvm.instrumentation.org.usvm.instrumentation.mock.MockHelper
+import org.usvm.instrumentation.mock.MockHelper
 import org.usvm.instrumentation.testcase.api.*
 import org.usvm.instrumentation.collector.trace.MockCollector
 import org.usvm.instrumentation.collector.trace.MockCollector.MockValueArrayWrapper
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/instrumentation.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/instrumentation.kt
index c9802d03e5..2ccfa63347 100644
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/instrumentation.kt
+++ b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/instrumentation.kt
@@ -1,3 +1,4 @@
+package  org.usvm.instrumentation.util
 import java.nio.file.Path
 import java.nio.file.Paths
 import java.util.*
diff --git a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/sandbox.kt b/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/sandbox.kt
deleted file mode 100644
index 2cff35cf6a..0000000000
--- a/usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/util/sandbox.kt
+++ /dev/null
@@ -1,35 +0,0 @@
-//package org.usvm.instrumentation.util
-//
-//import sun.security.provider.PolicyFile
-//import java.nio.file.Files
-//import java.nio.file.Paths
-//import java.security.*
-//import java.security.cert.Certificate
-//
-//object SecurityManager {
-//    private val policyPath = Paths.get("./usvm.policy")
-//
-//    private val permissions = Permissions()
-//    private val allCodeSource = CodeSource(null, emptyArray<Certificate>())
-//
-//    init {
-//        permissions.add(RuntimePermission("accessDeclaredMembers"))
-//        permissions.add(RuntimePermission("getStackWalkerWithClassReference"))
-//        permissions.add(RuntimePermission("getClassLoader"))
-//
-//        if (Files.exists(policyPath)) {
-//            val policyFile = PolicyFile(policyPath.toUri().toURL())
-//            policyFile.getPermissions(allCodeSource).elements().toList().forEach { permissions.add(it) }
-//        }
-//    }
-//
-////    fun <T> sandbox(block: () -> T): T {
-////        val acc = AccessControlContext(arrayOf(ProtectionDomain(allCodeSource, permissions)))
-////        return try {
-////            AccessController.doPrivileged(PrivilegedAction { block() }, acc)
-////        } catch (e: PrivilegedActionException) {
-////            throw e.exception
-////        }
-////    }
-//
-//}
diff --git a/usvm-jvm-instrumentation/src/test/kotlin/org/usvm/instrumentation/executor/SimpleUTestConcreteExecutor.kt b/usvm-jvm-instrumentation/src/test/kotlin/org/usvm/instrumentation/executor/SimpleUTestConcreteExecutor.kt
index 02194b592e..62799aeeae 100644
--- a/usvm-jvm-instrumentation/src/test/kotlin/org/usvm/instrumentation/executor/SimpleUTestConcreteExecutor.kt
+++ b/usvm-jvm-instrumentation/src/test/kotlin/org/usvm/instrumentation/executor/SimpleUTestConcreteExecutor.kt
@@ -36,14 +36,14 @@ class SimpleUTestConcreteExecutor: UTestConcreteExecutorTest() {
     fun `simple test`() = executeTest {
         val uTest = UTestCreator.C.lol(jcClasspath)
         val res = uTestConcreteExecutor.executeAsync(uTest)
-        check(res is UTestExecutionSuccessResult)
+        assertIs<UTestExecutionSuccessResult>(res)
     }
 
     @Test
     fun `arithmetic operation`() = executeTest {
         val uTest = UTestCreator.A.arithmeticOperation(jcClasspath)
         val res = uTestConcreteExecutor.executeAsync(uTest)
-        check(res is UTestExecutionSuccessResult)
+        assertIs<UTestExecutionSuccessResult>(res)
         val result = res.result
         assertIs<UTestConstantDescriptor.Int>(result)
         assertEquals(239, result.value)
@@ -53,8 +53,7 @@ class SimpleUTestConcreteExecutor: UTestConcreteExecutorTest() {
     fun `exception`() = executeTest {
         val uTest = UTestCreator.A.exception(jcClasspath)
         val res = uTestConcreteExecutor.executeAsync(uTest)
-        assert(res is UTestExecutionExceptionResult)
-        res as UTestExecutionExceptionResult
+        assertIs<UTestExecutionExceptionResult>(res)
         check(res.cause.stackTrace.isNotEmpty())
         assertEquals(res.cause.type, jcClasspath.findTypeOrNull<IllegalArgumentException>())
     }
@@ -63,7 +62,7 @@ class SimpleUTestConcreteExecutor: UTestConcreteExecutorTest() {
     fun `java reflection test`() = executeTest {
         val uTest = UTestCreator.A.getNumberOfClassConstructors(jcClasspath)
         val res = uTestConcreteExecutor.executeAsync(uTest)
-        check(res is UTestExecutionSuccessResult)
+        assertIs<UTestExecutionSuccessResult>(res)
         val result = res.result
         assertNotNull(result)
         assertIs<UTestConstantDescriptor.Int>(result)