docs: def mixin (cls):
      """
      A decorator which adds event methods to a class giving it the ability to
      bind to and trigger events
  
      :param cls: the class to add the event logic to
      :type cls: class
      :return: the modified class
      :rtype: class
      """
      cls._events = {}
      cls.bind = Pyevent.bind.__func__
      cls.unbind = Pyevent.unbind.__func__
      cls.trigger = Pyevent.trigger.__func__
      return cls