SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function firstNonDefault (alias result) (children 1)
     ExpressionList (children 2)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'[]\'
        Literal \'Array(UInt8)\'
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'[1, 2, 3]\'
        Literal \'Array(UInt8)\'
