sig
val debug : ('a, unit, string, unit) Pervasives.format4 -> 'a
val info : ('a, unit, string, unit) Pervasives.format4 -> 'a
val warning : ('a, unit, string, unit) Pervasives.format4 -> 'a
val error : ('a, unit, string, unit) Pervasives.format4 -> 'a
val string_of_exception : exn -> string
end