Return the source mapping where the event is declared

        Args:
            event (str): event name
        Returns:
            (dict): sourceMapping

def get_source_event_declaration(self, event):
        """ Return the source mapping where the event is declared

        Args:
            event (str): event name
        Returns:
            (dict): sourceMapping
        """
        return next((x.source_mapping for x in self.events if x.name == event))