public static String substVars(String val, PropertyContainer pc1) {
    return substVars(val, pc1, null);
  }
@Test
  public void nonCircularGraphShouldWork() {
    context.putProperty("A", "${B} and ${C}");
    context.putProperty("B", "${B1}");
    context.putProperty("B1", "B1-value");
    context.putProperty("C", "${C1} and ${B}");
    context.putProperty("C1", "C1-value");

    String result = OptionHelper.substVars("${A}", context);
    assertEquals("B1-value and C1-value and B1-value", result);
  }