SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function CAST (alias x) (children 1)
     ExpressionList (children 2)
      Function toNullable (children 1)
       ExpressionList (children 1)
        Function toInt8 (children 1)
         ExpressionList (children 1)
          Literal UInt64_0
      Literal \'Int32\'
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x