val action_none : string -> (unit -> unit) -> unit
val action_one : string -> string * 'a arg -> ('a -> unit) -> unit
val action_two : string -> string * 'a arg * string * 'b arg -> ('a * 'b -> unit) -> unit
val action_none : string -> (unit -> unit) -> unit
val action_one : string -> string * 'a arg -> ('a -> unit) -> unit
val action_two : string -> string * 'a arg * string * 'b arg -> ('a * 'b -> unit) -> unit