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 3)
    Function lambda (children 1)
     ExpressionList (children 1)
      Literal UInt64_1
    Function lambda (children 1)
     ExpressionList (children 1)
      Literal NULL
    Function lambda (children 1)
     ExpressionList (children 1)
      Literal Array_[UInt64_1, UInt64_2, UInt64_3]