sig
type tag = (string * string) list
val read : string -> Mp3tag.Id3v2.tag
val write : Mp3tag.Id3v2.tag -> ?src:string -> string -> unit
val merge : Mp3tag.Id3v2.tag -> Mp3tag.Id3v2.tag -> Mp3tag.Id3v2.tag
val no_tag : Mp3tag.Id3v2.tag
end