docs: void unregistered() {
          try {
              if (!m_alreadyStopped) {
                  try {
                      safeStopping();
                  } finally {
                      try {
                          m_writeStream.shutdown();
                      } finally {
                          m_readStream.shutdown();
                      }
                  }
              }
          } finally {
              networkLog.debug("Closing channel " + m_threadName);
              try {
                  m_sc.close();
              } catch (IOException e) {
                  networkLog.warn(e);
              }
          }
      }