module Debug:
Debug builds a pool in which every function can run invariant on its pool
      argument(s) and/or print a debug message to stderr, as determined by
      !check_invariant and !show_messages, which are initially both true.
      The performance of the pool resulting from Debug is much worse than that of the
      input Pool, even with all the controls set to false.
| Parameters: | 
  | 
include Pool_intf.Pool.S
val check_invariant : bool Pervasives.refval show_messages : bool Pervasives.ref