code: private void write(IoSession session, IoBuffer data) {
          IoBuffer dest = buffersMap.putIfAbsent(session,
                  new IoBufferLazyInitializer(bufferSize));
  
          write(session, data, dest);
      }
docs: Writes an {@link IoBuffer} to the session's buffer.
  
  @param session the session to which a write is requested
  @param data the data to buffer