svoid addToDefaultVMArgs(S newArgs) {
  LS split = splitJavaVMArgs(newArgs);
  S originalArgs = javaxDefaultVMArgs(), args = originalArgs;
  for (S s : split) {
    S arg = takeFirst(s, smartIndexOf(s, '='));
    if (contains(args, arg)) continue;
    args += " " + s;
  }
  if (neq(args, originalArgs))
    setDefaultVMArgs(args);
}