Bind an event to a callback

        :param event_name: The name of the event to bind to.
        :type event_name: str

        :param callback: The callback to notify of this event.

def bind(self, event_name, callback):
        """Bind an event to a callback

        :param event_name: The name of the event to bind to.
        :type event_name: str

        :param callback: The callback to notify of this event.
        """

        if event_name not in self.event_callbacks.keys():
            self.event_callbacks[event_name] = []

        self.event_callbacks[event_name].append(callback)