def get_object_index(self, key):
        """|coro|

        Mainly for internal use with get_operator,
        returns the "location" index for the key in the definitions

        Returns
        -------
        str
            the object's location index"""
        defns = yield from self.get_definitions()

        for x in defns:
            if key in x and "objectIndex" in defns[x]:
                return defns[x]["objectIndex"]

        return None
|coro|

        Mainly for internal use with get_operator,
        returns the "location" index for the key in the definitions

        Returns
        -------
        str
            the object's location index