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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def checkForeignKeys(self, engine: Engine) -> None: """ Check Foreign Keys Log any foreign keys that don't have indexes assigned to them. This is a performance issue. """

        missing = (sqlalchemy_utils.functions
                   .non_indexed_foreign_keys(self._metadata, engine=engine))

        for table, keys in missing.items():
            for key in keys:
                logger.warning("Missing index on ForeignKey %s" % key.columns)