SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function mapApply (children 1)
     ExpressionList (children 2)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 2)
          Identifier x
          Identifier y
        Literal Tuple_(\'x\', \'y\')
      Function map (children 1)
       ExpressionList (children 4)
        Literal UInt64_1
        Literal UInt64_0
        Literal UInt64_2
        Literal UInt64_0