public void accept(@NotNull PsiElementVisitor visitor) {
   if (visitor instanceof XQueryVisitor) ((XQueryVisitor) visitor).visitLetBinding(this);
   else super.accept(visitor);
 }
 public void accept(@NotNull PsiElementVisitor visitor) {
   if (visitor instanceof XQueryVisitor) ((XQueryVisitor) visitor).visitCastableOperator(this);
   else super.accept(visitor);
 }