code: public void sendPendingServiceCallsCloseError() {
          if (pendingCalls != null && !pendingCalls.isEmpty()) {
              if (log.isDebugEnabled()) {
                  log.debug("Connection calls pending: {}", pendingCalls.size());
              }
              for (IPendingServiceCall call : pendingCalls.values()) {
                  call.setStatus(Call.STATUS_NOT_CONNECTED);
                  for (IPendingServiceCallback callback : call.getCallbacks()) {
                      callback.resultReceived(call);
                  }
              }
          }
      }
docs: When the connection has been closed, notify any remaining pending service calls that they have failed because the connection is
  broken. Implementors of IPendingServiceCallback may only deduce from this notification that it was not possible to read a result for
  this service call. It is possible that (1) the service call was never written to the service, or (2) the service call was written to
  the service and although the remote method was invoked, the connection failed before the result could be read, or (3) although the
  remote method was invoked on the service, the service implementor detected the failure of the connection and performed only partial
  processing. The caller only knows that it cannot be confirmed that the callee has invoked the service call and returned a result.