docs: private static ImmutableList<String> setCompilePolicyToByFile(ImmutableList<String> args) {
      for (String arg : args) {
        if (arg.startsWith("-XDcompilePolicy")) {
          String value = arg.substring(arg.indexOf('=') + 1);
          checkCompilePolicy(value);
          return args; // don't do anything if a valid policy is already set
        }
      }
      return ImmutableList.<String>builder().addAll(args).add("-XDcompilePolicy=byfile").build();
    }