val tester : 'a Exenum.t ‑> ?from:Z.t ‑> ?upto:Z.t ‑> ?verbose_period:int ‑> ?tos:('a ‑> string) ‑> len:int ‑> ('a ‑> unit Lwt.t) ‑> unit Lwt.t
Note that tester
does not comply with non-lwt exceptions: some exceptions may get lost.
verbose_period
tests.len
consecutive values are enumerated, then the index is doubled (and we loop)