code: def get_exception(self):
          
          self.lock.acquire()
          try:
              e = self.saved_exception
              self.saved_exception = None
              return e
          finally:
              self.lock.release()
docs: Return any exception that happened during the last server request.
          This can be used to fetch more specific error information after using
          calls like `start_client`.  The exception (if any) is cleared after
          this call.
  
          :return:
              an exception, or ``None`` if there is no stored exception.
  
          .. versionadded:: 1.1