fix some warnings and remove some dead code.

Author: Aurélien Richez

src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala

@@ -942,7 +942,7 @@ class FastSync(
       }
 
     def assignBlockchainWork(peerWithInfo: PeerWithInfo): Unit = {
-      val PeerWithInfo(peer, peerInfo) = peerWithInfo
+      val PeerWithInfo(peer, _) = peerWithInfo
       log.debug(s"Assigning blockchain work for peer [{}]", peer.id.value)
       if (syncState.receiptsQueue.nonEmpty) {
         requestReceipts(peer)

src/main/scala/io/iohk/ethereum/db/storage/AppStateStorage.scala

@@ -6,18 +6,11 @@ import akka.util.ByteString
 
 import scala.collection.immutable.ArraySeq
 
-import boopickle.Default.Unpickle
-import boopickle.DefaultBasic._
-import boopickle.Pickler
-
 import io.iohk.ethereum.db.dataSource.DataSource
 import io.iohk.ethereum.db.dataSource.DataSourceBatchUpdate
 import io.iohk.ethereum.db.storage.AppStateStorage._
 import io.iohk.ethereum.domain.appstate.BestBlockInfo
-import io.iohk.ethereum.utils.ByteUtils.byteSequenceToBuffer
-import io.iohk.ethereum.utils.ByteUtils.compactPickledBytes
 import io.iohk.ethereum.utils.Hex
-import io.iohk.ethereum.utils.Picklers._
 
 /** This class is used to store app state variables
   *   Key: see AppStateStorage.Keys

src/main/scala/io/iohk/ethereum/domain/BlockchainWriter.scala

@@ -51,7 +51,7 @@ class BlockchainWriter(
 
     // not transactional part
     // the best blocks data will be persisted only when the cache will be persisted
-    stateStorage.onBlockSave(block.header.number, appStateStorage.getBestBlockNumber())(persistBestBlocksData)
+    stateStorage.onBlockSave(block.header.number, appStateStorage.getBestBlockNumber())(persistBestBlocksData _)
   }
 
   def storeReceipts(blockHash: ByteString, receipts: Seq[Receipt]): DataSourceBatchUpdate =

src/test/scala/io/iohk/ethereum/jsonrpc/EthBlocksServiceSpec.scala

@@ -412,7 +412,7 @@ class EthBlocksServiceSpec
     )
   }
 
-  class TestSetup(implicit system: ActorSystem) extends MockFactory with EphemBlockchainTestSetup {
+  class TestSetup() extends MockFactory with EphemBlockchainTestSetup {
     val blockGenerator: PoWBlockGenerator = mock[PoWBlockGenerator]
     val appStateStorage: AppStateStorage = mock[AppStateStorage]
 

src/test/scala/io/iohk/ethereum/jsonrpc/EthProofServiceSpec.scala

@@ -214,7 +214,7 @@ class EthProofServiceSpec
     )
   }
 
-  class TestSetup(implicit system: ActorSystem) extends MockFactory with EphemBlockchainTestSetup with ApisBuilder {
+  class TestSetup() extends MockFactory with EphemBlockchainTestSetup with ApisBuilder {
 
     val blockGenerator: PoWBlockGenerator = mock[PoWBlockGenerator]
     val address: Address = Address(ByteString(Hex.decode("abbb6bebfa05aa13e908eaa492bd7a8343760477")))

src/test/scala/io/iohk/ethereum/jsonrpc/EthUserServiceSpec.scala

@@ -139,7 +139,7 @@ class EthUserServiceSpec
     response.runSyncUnsafe() shouldEqual Right(GetTransactionCountResponse(BigInt(999)))
   }
 
-  class TestSetup(implicit system: ActorSystem) extends MockFactory with EphemBlockchainTestSetup {
+  class TestSetup() extends MockFactory with EphemBlockchainTestSetup {
     lazy val ethUserService = new EthUserService(
       blockchain,
       blockchainReader,

src/test/scala/io/iohk/ethereum/transactions/LegacyTransactionHistoryServiceSpec.scala

@@ -160,7 +160,7 @@ class LegacyTransactionHistoryServiceSpec
       )
 
       def makeReceipts(block: Block): Seq[Receipt] =
-        block.body.transactionList.map(tx => Receipt(HashOutcome(block.hash), BigInt(21000), ByteString("foo"), Nil))
+        block.body.transactionList.map(_ => Receipt(HashOutcome(block.hash), BigInt(21000), ByteString("foo"), Nil))
 
       for {
         _ <- Task {