code: private boolean finish(boolean releaseAll) {
          close();
          try {
              checkException();
              return isNotEmpty(inboundMessages) || isNotEmpty(outboundMessages);
          } finally {
              if (releaseAll) {
                  releaseAll(inboundMessages);
                  releaseAll(outboundMessages);
              }
          }
      }
docs: Mark this {@link Channel} as finished. Any further try to write data to it will fail.
  
  @param releaseAll if {@code true} all pending message in the inbound and outbound buffer are released.
  @return bufferReadable returns {@code true} if any of the used buffers has something left to read