docs: private Channel unlinkFromOrigin() {
          if (originResponseReceiver != null) {
              originResponseReceiver.unlinkFromClientRequest();
              originResponseReceiver = null;
          }
  
          if (concurrentReqCount > 0) {
              origin.recordProxyRequestEnd();
              concurrentReqCount--;
          }
  
          Channel origCh = null;
          if (originConn != null) {
              origCh = originConn.getChannel();
              originConn = null;
          }
          return origCh;
      }