svoid test_roundUpToPowerOfTen() {
  for (double exp = -1; exp <= log10(Int.MAX_VALUE-100); exp += 0.1) {
    int n = iround(exp10(exp));
    long answer = roundUpToPowerOfTen_double(n);
    long toCheck = roundUpToPowerOfTen(n);
    assertEqualsVerbose(str(n), answer, toCheck);
  }
}