code: def click(self):
          
          if self.is_checkable():        
              if self.is_checked(): self.set_checked(False)
              else:                 self.set_checked(True)
              self.signal_clicked.emit(self.is_checked())
          else:
              self.signal_clicked.emit(True)
          return self
docs: Pretends to user clicked it, sending the signal and everything.