code: def is_defined(self, objtxt, force_import=False):
          
          if self._reading:
              return
          wait_loop = QEventLoop()
          self.sig_got_reply.connect(wait_loop.quit)
          self.silent_exec_method(
              "get_ipython().kernel.is_defined('%s', force_import=%s)"
              % (objtxt, force_import))
          wait_loop.exec_()
  
          # Remove loop connection and loop
          self.sig_got_reply.disconnect(wait_loop.quit)
          wait_loop = None
  
          return self._kernel_reply
docs: Return True if object is defined