SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function isConstant (children 1)
     ExpressionList (children 1)
      Function format (children 1)
       ExpressionList (children 2)
        Literal \'{}, world\'
        Literal \'Hello\'
