svoid test_rebaseZeroTo() {
  testFunctionValues_twoArgs_flat((IF2<Double, Double, S>) (a, b) -> formatDouble3(rebaseZeroTo(a, b)),
    0.1, 0.0, formatDouble3(0.1),
    0.1, 0.5, formatDouble3(0.55),
    0.1, 1.0, formatDouble3(1.0),
    0.5, 0.5, formatDouble3(0.75),
  );
}