public override void VisitAdditionalFromClause(Remotion.Linq.Clauses.AdditionalFromClause fromClause, QueryModel queryModel, int index)
 {
     _isInstanceQuery = false;
     var fromVar = _queryBuilder.AddFromPart(fromClause);
     if (!(fromClause.FromExpression is ConstantExpression))
     {
         var fromExpression =
             SparqlGeneratorWhereExpressionTreeVisitor.GetSparqlExpression(fromClause.FromExpression,
                                                                           _queryBuilder);
         if (fromExpression is SelectVariableNameExpression)
         {
             _queryBuilder.RenameVariable((fromExpression as SelectVariableNameExpression).Name,fromVar);
         }
     }
     base.VisitAdditionalFromClause(fromClause, queryModel, index);
 }