void IVisitor.VisitBefore(WithDefinition withDefinition)
 {
     this.ParentExists(withDefinition);
 }
 void IVisitor.VisitOnAs(WithDefinition withDefinition, int offset)
 {
     this.ParentExists(withDefinition);
 }
 void IVisitor.VisitAfter(WithDefinition withDefinition)
 {
     this.ParentExists(withDefinition);
 }