code: private Packet enqueue(byte[] data) {
          if (prepend) {
              stack.push(data);
          } else {
              queue.offerLast(data);
          }
          
          return this;
      }
docs: A helper method that eliminates duplicate code and enqueues a {@code byte[]} to the backing {@link Deque}
  (either at the front or back depending on the value of {@code prepend}).
  
  @param data The data to be written.
  @return This {@link Packet} to allow for chained writes.