Application defined properties on the message.

        :param value: The application properties for the EventData.
        :type value: dict

def application_properties(self, value):
        """
        Application defined properties on the message.

        :param value: The application properties for the EventData.
        :type value: dict
        """
        self._app_properties = value
        properties = dict(self._app_properties)
        self.message.application_properties = properties