code: def _post_deactivate_injection(self):
          
          # Lets be sure that active is really set to false.
          self.active = False
          self.app.signals.send("plugin_deactivate_post", self)
          # After all receivers are handled. We start to clean up signals and receivers of this plugin
          # Attention: This signal clean must not be called via a signal (like in other patterns),
          # because the call order of receivers is not clear and a signal/receiver clean up would prohibit the call
          # of all "later" receivers.
          self.signals.deactivate_plugin_signals()
docs: Injects functions after the deactivation routine of child classes got called
          :return: None