@Override
  public void removeBlockAddedListener(final long listenerIdentifier) {
    blockchain.removeObserver(listenerIdentifier);
  }
Constructor for BesuEventsImpl

@param blockchain An instance of Blockchain
@param blockBroadcaster An instance of BlockBroadcaster
@param transactionPool An instance of TransactionPool
@param syncState An instance of SyncState
@param badBlockManager A cache of bad blocks encountered on the network
app/src/main/java/org/hyperledger/besu/services/BesuEventsImpl.java