public static String substVars(String val, PropertyContainer pc1) {
    return substVars(val, pc1, null);
  }
@Test
  public void testSubstVarsVariableNotClosed() {
    String noSubst = "testing if ${v1 works";
    
    try {
      @SuppressWarnings("unused")
      String result = OptionHelper.substVars(noSubst, context);
      fail();
    } catch (IllegalArgumentException e) {
      //ok
    }
  }