"ratio of equals/hashCode/compareTo operations to build with %s entries versus %s"
                  + " entries",
              largeSize, smallSize)
          .that(ratio)
          .isAtMost(
              2
                  * constructionAsymptotics.applyAsDouble(largeSize)
                  / constructionAsymptotics.applyAsDouble(smallSize));
      // allow up to 2x wobble in the constant factors
    }

    // simultaneous update for same key, some null, some non-null
    doParallelCacheOp(
        count, n -> cache.asMap().compute(key, (k, v) -> n % 2 == 0 ? v + delimiter + n : null));
    assertThat(cache.size()).isAtMost(1);
  }

  public void testCompute() {
    cache.put(key, "1");
    // simultaneous deletion
    doParallelCacheOp(count, n -> cache.asMap().compute(key, (k, v) -> null));