public void testOptimalNumOfHashFunctionsRounding() {
    assertEquals(7, BloomFilter.optimalNumOfHashFunctions(319, 3072));
  }

  /** Tests that we always get a non-negative optimal size. */
  public void testOptimalSize() {
    for (int n = 1; n < 1000; n++) {
      for (double fpp = Double.MIN_VALUE; fpp < 1.0; fpp += 0.001) {
        assertTrue(BloomFilter.optimalNumOfBits(n, fpp) >= 0);
      }
    }