Class type Js_of_ocaml__Form.formData
method append : 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 append_blob : Js_of_ocaml.Js.js_string Js_of_ocaml.Js.t -> Js_of_ocaml.File.blob Js_of_ocaml.Js.t -> unit Js_of_ocaml.Js.meth