@Override
  public void destroy() {
    Connection conn = clientToServerConn.get();
    if (conn != null) {
      manager.connectionCrashed(conn);
    } // else someone else destroyed it
  }
A wrapper that holds a client to server connection and a server to client connection.

The clientToServerConnection should not be used outside of this class.
geode-core/src/main/java/org/apache/geode/cache/client/internal/QueueConnectionImpl.java