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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 _create_index(self, table_name, index_columns):
 """ Creates an index over multiple columns of a given table. Parameters table_name : str index_columns : iterable of str Which columns should be indexed """


        logger.info(
            "Creating index on %s (%s)",
            table_name,
            ", ".join(index_columns))
        index_name = "%s_index_%s" % (
            table_name,
            "_".join(index_columns))
        self.connection.execute(
            "CREATE INDEX IF NOT EXISTS %s ON %s (%s)" % (
                index_name,
                table_name,
                ", ".join(index_columns)))