public virtual void VisitQueryGroupClause(QueryGroupClause queryGroupClause)
{
StartNode(queryGroupClause);
WriteKeyword(QueryGroupClause.GroupKeywordRole);
Space();
queryGroupClause.Projection.AcceptVisitor(this);
Space();
WriteKeyword(QueryGroupClause.ByKeywordRole);
Space();
queryGroupClause.Key.AcceptVisitor(this);
EndNode(queryGroupClause);
}