Method enqueue

netty/src/main/java/io/grpc/netty/WriteQueue.java:79–91

Enqueue a write command on the channel. @param command a write to be executed on the channel. @param flush true if a flush of the write should be schedule, false if a later call to enqueue will schedule the flush.

(QueuedCommand command, boolean flush)

   *              enqueue will schedule the flush.
   */
  @CanIgnoreReturnValue
  ChannelFuture enqueue(QueuedCommand command, boolean flush) {
    // Detect erroneous code that tries to reuse command objects.
    Preconditions.checkArgument(command.promise() == null, "promise must not be set on command");

    ChannelPromise promise = channel.newPromise();
    command.promise(promise);
    queue.add(command);
    if (flush) {
      scheduleFlush();
    }
    return promise;
  }

  /**
   * Enqueue the runnable. It is not safe for another thread to queue an Runnable directly to the