code: def connect(self, slot):
          
          self._ensure_slot_args(slot)
          if not self.is_connected(slot):
              self.slots.append(slot)
docs: Connect ``slot`` to this singal.
  
          Args:
              slot (callable): Callable object wich accepts keyword arguments.
  
          Raises:
              InvalidSlot: If ``slot`` doesn't accept keyword arguments.