@Test
public void testSubstitutions2() throws Exception {
  StringBuilder sb = new StringBuilder();
  sb.append("prop.1 = one\n");
  sb.append("prop.2 = two\n");
  sb.append("prop.3 = three\n");
  sb.append("prop.4 = ${prop.1}-${prop.2}-${prop.3}-four\n");
  try (Reader r = new StringReader(sb.toString())) {
    TypedProperties props = ConfigurationHelper.loadAndResolve(r);
    assertTrue(props.containsKey("prop.4"));
    assertEquals("one-two-three-four", props.getProperty("prop.4"));
  }
}