SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    Function lambda (alias lambda_1) (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)
    Literal UInt64_3
    Function arrayMap (children 1)
     ExpressionList (children 2)
      Identifier lambda_1 (alias lambda_2)
      Literal Array_[UInt64_1, UInt64_2, UInt64_3]
    Function arrayMap (children 1)
     ExpressionList (children 2)
      Identifier lambda_2
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal Array_[\'1\', \'2\', \'3\']
   Function toNullable (children 1)
    ExpressionList (children 1)
     Literal UInt64_9
   ExpressionList (children 1)
    Identifier lambda_2
