code: void unregistered() {
          try {
              if (!m_alreadyStopped) {
                  m_alreadyStopped = true;
                  try {
                      m_handler.stopped(this);
                  } finally {
                      try {
                          m_writeStream.shutdown();
                      } finally {
                          if (m_readStream != null) {
                              m_readStream.shutdown();
                          }
                      }
                  }
              }
          } finally {
              networkLog.debug("Closing channel " + m_toString);
              try {
                  m_channel.close();
              } catch (IOException e) {
                  networkLog.warn(e);
              }
          }
      }
docs: Called when unregistration is complete and the Connection can no
  longer be interacted with.
  
  Various error paths fall back to unregistering so it can happen multiple times and is really
  annoying. Suppress it here with a flag