SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   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 id
   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]
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test_table