Run a Sparql query.

        :param query: sparql query string
        :rtype: list of dictionary

def sparql_query(self, query, flush=None, limit=None):
        """
        Run a Sparql query.

        :param query: sparql query string
        :rtype: list of dictionary
        """
        return self.find_statements(query, language='sparql', type='tuples',
            flush=flush, limit=limit)