private void SetupDb(GraphDatabaseSettings.SchemaIndex schemaIndex)
        {
            TestGraphDatabaseFactory dbFactory = new TestGraphDatabaseFactory();
            GraphDatabaseBuilder     builder   = dbFactory.NewEmbeddedDatabaseBuilder(_directory.storeDir()).setConfig(GraphDatabaseSettings.default_schema_provider, schemaIndex.providerName());

            _db = builder.NewGraphDatabase();
        }