SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function array (children 1)
     ExpressionList (children 2)
      Literal \'Hello\'
      Function concat (children 1)
       ExpressionList (children 2)
        Literal \'wor\'
        Literal \'ld\'