sig
type t = Core.Std.Time.Span.t Core.Std.Validated.t
val create : Core.Std.Time.Span.t -> t Core_kernel.Or_error.t
val create_exn : Core.Std.Time.Span.t -> t
val raw : t -> Core.Std.Time.Span.t
val t_of_sexp : Sexplib.Sexp.t -> t
val sexp_of_t : t -> Sexplib.Sexp.t
end