Ast_helper.Attr
val mk : ?loc:Ocaml_parsing.Ast_helper.loc -> Ocaml_parsing.Ast_helper.str -> Ocaml_parsing.Parsetree.payload -> Ocaml_parsing.Parsetree.attribute
val as_tuple : Ocaml_parsing.Parsetree.attribute -> Ocaml_parsing.Ast_helper.str * Ocaml_parsing.Parsetree.payload