docs: def sparql_query(self, collection_name, query):
          """ Submit a sparql query to the server to search metadata
          and annotations.
  
          :type collection_name: String
          :param collection_name: the name of the collection to search
          :type query: String
          :param query: the sparql query
  
          :rtype: Dict
          :returns: the query result from the server as a Python dictionary
              following the format of the SPARQL JSON result format documented
              at http://www.w3.org/TR/rdf-sparql-json-res/
  
          :raises: APIError if the request was not successful
  
  
          """
          request_url = '/sparql/' + collection_name + '?'
          request_url += urlencode((('query', query),))
  
          return self.api_request(request_url)