`method length : int Js_of_ocaml__.Js.readonly_prop`
`method key : int -> Js_of_ocaml__.Js.js_string Js_of_ocaml__.Js.t Js_of_ocaml__.Js.opt Js_of_ocaml__.Js.meth`
`method getItem : Js_of_ocaml__.Js.js_string Js_of_ocaml__.Js.t -> Js_of_ocaml__.Js.js_string Js_of_ocaml__.Js.t Js_of_ocaml__.Js.opt Js_of_ocaml__.Js.meth`
`method setItem : Js_of_ocaml__.Js.js_string Js_of_ocaml__.Js.t -> Js_of_ocaml__.Js.js_string Js_of_ocaml__.Js.t -> unit Js_of_ocaml__.Js.meth`
`method removeItem : Js_of_ocaml__.Js.js_string Js_of_ocaml__.Js.t -> unit Js_of_ocaml__.Js.meth`
`method clear : unit Js_of_ocaml__.Js.meth`