assertEquals("", is('a').retainFrom(""));
  }

  public void testPrecomputedOptimizations() {
    // These are testing behavior that's never promised by the API.
    // Some matchers are so efficient that it is a waste of effort to
    // build a precomputed version.
    CharMatcher m1 = is('x');
    assertSame(m1, m1.precomputed());
    assertEquals(m1.toString(), m1.precomputed().toString());

    CharMatcher m2 = anyOf("Az");

    assertEquals("", is('a').retainFrom(""));
  }

  public void testPrecomputedOptimizations() {
    // These are testing behavior that's never promised by the API.
    // Some matchers are so efficient that it is a waste of effort to
    // build a precomputed version.
    CharMatcher m1 = is('x');
    assertSame(m1, m1.precomputed());
    assertEquals(m1.toString(), m1.precomputed().toString());

    CharMatcher m2 = anyOf("Az");

never forgotten that, if you drink much from a bottle marked
`poison,' it is almost certain to disagree with you, sooner or
later.

  However, this bottle was NOT marked `poison,' so Alice ventured
to taste it, and finding it very nice, (it had, in fact, a sort
of mixed flavour of cherry-tart, custard, pine-apple, roast
turkey, toffee, and hot buttered toast,) she very soon finished
it off.

never forgotten that, if you drink much from a bottle marked
`poison,' it is almost certain to disagree with you, sooner or
later.

  However, this bottle was NOT marked `poison,' so Alice ventured
to taste it, and finding it very nice, (it had, in fact, a sort
of mixed flavour of cherry-tart, custard, pine-apple, roast
turkey, toffee, and hot buttered toast,) she very soon finished
it off.

   * uniform, the actual concurrency observed may vary. Ideally, you should choose a value to
   * accommodate as many threads as will ever concurrently modify the table. Using a significantly
   * higher value than you need can waste space and time, and a significantly lower value can lead
   * to thread contention. But overestimates and underestimates within an order of magnitude do not

   * uniform, the actual concurrency observed may vary. Ideally, you should choose a value to
   * accommodate as many threads as will ever concurrently modify the table. Using a significantly
   * higher value than you need can waste space and time, and a significantly lower value can lead
   * to thread contention. But overestimates and underestimates within an order of magnitude do not

	}

	// queue replication heal in a goroutine to avoid holding up mrf save routine
	go func() {
		for vID, e := range mrfRec.Entries {
			ctx, cancel := context.WithTimeout(p.ctx, time.Second) // Do not waste more than a second on this.

			oi, err := p.objLayer.GetObjectInfo(ctx, e.Bucket, e.Object, ObjectOptions{
				VersionID: vID,
			})
			cancel()
			if err != nil {
				continue
			}