code: def hook_inform(self, inform_name, callback):
          
          # Do not hook the same callback multiple times
          if callback not in self._inform_hooks[inform_name]:
              self._inform_hooks[inform_name].append(callback)
docs: Hookup a function to be called when an inform is received.
  
          Useful for interface-changed and sensor-status informs.
  
          Parameters
          ----------
          inform_name : str
              The name of the inform.
          callback : function
              The function to be called.