public static String substVars(String val, PropertyContainer pc1) {
    return substVars(val, pc1, null);
  }
@Test
  public void jackrabbit_standalone() {
    String r = OptionHelper.substVars("${jackrabbit.log:-${repo:-jackrabbit}/log/jackrabbit.log}", context);
    assertEquals("jackrabbit/log/jackrabbit.log", r);
  }