public void testFuzzyEqualsTwoNaNs() {
    for (double tolerance : TOLERANCE_CANDIDATES) {
      assertTrue(DoubleMath.fuzzyEquals(Double.NaN, Double.NaN, tolerance));
    }
  }

  public void testFuzzyEqualsZeroTolerance() {
    // make sure we test -0 tolerance
    for (double zero : Doubles.asList(0.0, -0.0)) {
      for (double a : ALL_DOUBLE_CANDIDATES) {
        for (double b : ALL_DOUBLE_CANDIDATES) {