SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function lambda (alias lambda) (children 1)
     ExpressionList (children 2)
      Function tuple (children 1)
       ExpressionList (children 1)
        Identifier x
      Function toString (children 1)
       ExpressionList (children 1)
        Identifier x
   ExpressionList (children 1)
    Function arrayMap (children 1)
     ExpressionList (children 2)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 1)
          Identifier x
        Function arrayMap (children 1)
         ExpressionList (children 2)
          Function lambda (children 1)
           ExpressionList (children 2)
            Function tuple (children 1)
             ExpressionList (children 1)
              Identifier y
            Function concat (children 1)
             ExpressionList (children 3)
              Function lambda (children 1)
               ExpressionList (children 1)
                Identifier x
              Literal \'_\'
              Function lambda (children 1)
               ExpressionList (children 1)
                Identifier y
          Literal Array_[UInt64_1, UInt64_2, UInt64_3]
      Literal Array_[UInt64_1, UInt64_2, UInt64_3]