code: public boolean execute(FutureOperation operation)
      {
          stateCheck(State.RUNNING, State.HEALTH_CHECKING);
  
          operation.setLastNode(this);
          Channel channel = getConnection();
          if (channel != null)
          {
              inProgressMap.put(channel, operation);
              ChannelFuture writeFuture = channel.writeAndFlush(operation);
              writeFuture.addListener(writeListener);
              logger.debug("Operation {} being executed on RiakNode {}:{}",
                           System.identityHashCode(operation), remoteAddress, port);
              return true;
          }
          else
          {
              logger.debug("Operation {} not being executed Riaknode {}:{}; no connections available",
                           System.identityHashCode(operation), remoteAddress, port);
              return false;
          }
      }
docs: Submits the operation to be executed on this node.
  
  @param operation The operation to perform
  @return {@code true} if this operation was accepted, {@code false} if there
  were no available connections.
  @throws IllegalStateException    if this node is not in the {@code RUNNING} or {@code HEALTH_CHECKING} state
  @throws IllegalArgumentException if the protocol required for the operation is not supported by this node