Chore/upgrade mainnets v2

contracts/apps/UsingWitnet.sol

@@ -34,7 +34,7 @@ abstract contract UsingWitnet
         __witnet = _wrb;
         __witnetDefaultSLA = WitnetV2.RadonSLA({
             // Number of nodes in the Witnet blockchain that will take part in solving the data request:
-            committeeSize: 15,
+            committeeSize: 10,
             // Fee in $nanoWIT paid to every node in the Witnet blockchain involved in solving the data request:
             witnessingFeeNanoWit: 2 * 10 ** 8  // defaults to 0.2 $WIT
         });

contracts/core/customs/WitnetDeployerCfxCore.sol

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.8.0 <0.9.0;
+
+import "../WitnetProxy.sol";
+
+/// @notice WitnetDeployer contract used both as CREATE2 factory (EIP-1014) for Witnet artifacts, 
+/// @notice and CREATE3 factory (EIP-3171) for Witnet proxies, on the Conflux Core Ecosystem.
+/// @author Guillermo Díaz <[email protected]>
+
+contract WitnetDeployerCfxCore {
+
+    /// @notice Use given `_initCode` and `_salt` to deploy a contract into a deterministic address. 
+    /// @dev The address of deployed address will be determined by both the `_initCode` and the `_salt`, but not the address
+    /// @dev nor the nonce of the caller (i.e. see EIP-1014). 
+    /// @param _initCode Creation code, including construction logic and input parameters.
+    /// @param _salt Arbitrary value to modify resulting address.
+    /// @return _deployed Just deployed contract address.
+    function deploy(bytes memory _initCode, bytes32 _salt)
+        public
+        returns (address _deployed)
+    {
+        _deployed = determineAddr(_initCode, _salt);
+        if (_deployed.code.length == 0) {
+            assembly {
+                _deployed := create2(0, add(_initCode, 0x20), mload(_initCode), _salt)
+            }
+            require(_deployed != address(0), "WitnetDeployer: deployment failed");
+        }
+    }
+
+    /// @notice Determine counter-factual address of the contract that would be deployed by the given `_initCode` and a `_salt`.
+    /// @param _initCode Creation code, including construction logic and input parameters.
+    /// @param _salt Arbitrary value to modify resulting address.
+    /// @return Deterministic contract address.
+    function determineAddr(bytes memory _initCode, bytes32 _salt)
+        public view
+        returns (address)
+    {
+        return address(
+            (uint160(uint(keccak256(
+                abi.encodePacked(
+                    bytes1(0xff),
+                    address(this),
+                    _salt,
+                    keccak256(_initCode)
+                )
+            ))) & uint160(0x0fffFFFFFfFfffFfFfFFffFffFffFFfffFfFFFFf)
+            ) | uint160(0x8000000000000000000000000000000000000000)
+        );
+    }
+
+    function determineProxyAddr(bytes32 _salt) 
+        public view
+        returns (address)
+    {
+        return determineAddr(type(WitnetProxy).creationCode, _salt);
+    }
+
+    function proxify(bytes32 _proxySalt, address _firstImplementation, bytes memory _initData)
+        external 
+        returns (WitnetProxy)
+    {
+        address _proxyAddr = determineProxyAddr(_proxySalt);
+        if (_proxyAddr.code.length == 0) {
+            // deploy the WitnetProxy
+            deploy(type(WitnetProxy).creationCode, _proxySalt);
+            // settle first implementation address,
+            WitnetProxy(payable(_proxyAddr)).upgradeTo(
+                _firstImplementation, 
+                // and initialize it, providing
+                abi.encode(
+                    // the owner (i.e. the caller of this function)
+                    msg.sender,
+                    // and some (optional) initialization data
+                     _initData
+                )
+            );
+            return WitnetProxy(payable(_proxyAddr));
+        } else {
+            revert("WitnetDeployer: already proxified");
+        }
+    }
+
+}

contracts/core/customs/WitnetDeployerMeter.sol

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.8.0 <0.9.0;
+
+import "../WitnetProxy.sol";
+
+/// @notice WitnetDeployer contract used both as CREATE2 factory (EIP-1014) for Witnet artifacts, 
+/// @notice and CREATE3 factory (EIP-3171) for Witnet proxies, on the Meter Ecosystem.
+/// @author Guillermo Díaz <[email protected]>
+
+contract WitnetDeployerMeter {
+
+    /// @notice Use given `_initCode` and `_salt` to deploy a contract into a deterministic address. 
+    /// @dev The address of deployed address will be determined by both the `_initCode` and the `_salt`, but not the address
+    /// @dev nor the nonce of the caller (i.e. see EIP-1014). 
+    /// @param _initCode Creation code, including construction logic and input parameters.
+    /// @param _salt Arbitrary value to modify resulting address.
+    /// @return _deployed Just deployed contract address.
+    function deploy(bytes memory _initCode, bytes32 _salt)
+        public
+        returns (address _deployed)
+    {
+        _deployed = determineAddr(_initCode, _salt);
+        if (_deployed.code.length == 0) {
+            assembly {
+                _deployed := create2(0, add(_initCode, 0x20), mload(_initCode), _salt)
+            }
+            require(_deployed != address(0), "WitnetDeployerMeter: deployment failed");
+        }
+    }
+
+    /// @notice Determine counter-factual address of the contract that would be deployed by the given `_initCode` and a `_salt`.
+    /// @param _initCode Creation code, including construction logic and input parameters.
+    /// @param _salt Arbitrary value to modify resulting address.
+    /// @return Deterministic contract address.
+    function determineAddr(bytes memory _initCode, bytes32 _salt)
+        public view
+        returns (address)
+    {
+        return address(
+            uint160(uint(keccak256(
+                abi.encodePacked(
+                    bytes1(0xff),
+                    address(this),
+                    _salt,
+                    keccak256(_initCode)
+                )
+            )))
+        );
+    }
+
+    function determineProxyAddr(bytes32 _salt) 
+        public view
+        returns (address)
+    {
+        return determineAddr(type(WitnetProxy).creationCode, _salt);
+    }
+
+    function proxify(bytes32 _proxySalt, address _firstImplementation, bytes memory _initData)
+        external 
+        returns (WitnetProxy)
+    {
+        address _proxyAddr = determineProxyAddr(_proxySalt);
+        if (_proxyAddr.code.length == 0) {
+            // deploy the WitnetProxy
+            deploy(type(WitnetProxy).creationCode, _proxySalt);
+            // settle first implementation address,
+            WitnetProxy(payable(_proxyAddr)).upgradeTo(
+                _firstImplementation, 
+                // and initialize it, providing
+                abi.encode(
+                    // the owner (i.e. the caller of this function)
+                    msg.sender,
+                    // and some (optional) initialization data
+                     _initData
+                )
+            );
+            return WitnetProxy(payable(_proxyAddr));
+        } else {
+            revert("WitnetDeployerMeter: already proxified");
+        }
+    }
+
+}

contracts/core/customs/WitnetRequestFactoryCfxCore.sol

@@ -9,10 +9,6 @@ contract WitnetRequestFactoryCfxCore
     is
         WitnetRequestFactoryDefault
 {
-    function class() virtual override public view returns (string memory) {
-        return type(WitnetRequestFactoryCfxCore).name;
-    }
-
     constructor(
             WitnetOracle _witnet,
             WitnetRequestBytecodes _registry,

contracts/core/defaults/WitnetOracleTrustableBase.sol

@@ -657,7 +657,7 @@ abstract contract WitnetOracleTrustableBase
                     _batchResults[_i].queryId, 
                     string(abi.encodePacked(
                         class(),
-                        "invalid report data"
+                        ": invalid report data"
                     ))
                 );
             } else {