public void testGoodFastHash128() {
    HashTestUtils.check2BitAvalanche(Hashing.goodFastHash(128), 250, 0.20);
    HashTestUtils.checkAvalanche(Hashing.goodFastHash(128), 500, 0.17);
    HashTestUtils.checkNo2BitCharacteristics(Hashing.goodFastHash(128));
    HashTestUtils.checkNoFunnels(Hashing.goodFastHash(128));
    HashTestUtils.assertInvariants(Hashing.goodFastHash(128));
  }

          builder.put(element, element);
        }
        return builder.build();
      }
    };

    abstract Map<Element, Element> create(Collection<Element> contents);
  }

  @Param({"5", "50", "500", "5000", "50000"})
  private int size;

  // TODO: look at exact (==) hits vs. equals() hits?
  @Param("0.9")
  private double hitRate;

  @Param("true")
  private boolean isUserTypeFast;