def delete(rdf_url)
      begin
        graph = fetch_cached_graph(rdf_url)
        puts "[INFO] did not delete #{rdf_url}, it doesn't exist in the triplestore cache" if graph.nil?
        return true if graph.nil?

        statements = graph.each_statement.to_a
        @client.delete(statements)
        return true
      rescue => e
        raise TriplestoreAdapter::TriplestoreException, "delete #{rdf_url} from triplestore cache failed with exception: #{e.message}"
      end
    end
def delete(rdf_url)
      begin
        graph = fetch_cached_graph(rdf_url)
        puts "[INFO] did not delete #{rdf_url}, it doesn't exist in the triplestore cache" if graph.nil?
        return true if graph.nil?

        statements = graph.each_statement.to_a
        @client.delete(statements)
        return true
      rescue => e
        raise TriplestoreAdapter::TriplestoreException, "delete #{rdf_url} from triplestore cache failed with exception: #{e.message}"
      end
    end
Delete the graph from the triplestore cache

 @param [String] rdf_url
 @return [Boolean]