static double floatSumAsDouble(Iterable<Float> l) {
  double sum = 0;
  for (Float i : unnull(l))
    if (i != null) sum += i;
  ret sum;
}

static double floatSumAsDouble(float... l) {
  double sum = 0;
  if (l != null) for (float i : l)
    sum += i;
  ret sum;
}

Began life as a copy of #1024749