@Test
public void applySystemPropertiesShouldConvertOptsToSystemProps() {

    System.setProperty("c", "");
    Map<String, String> opts = new HashMap<>();
    opts.put("a", "1");
    opts.put("-Dc", "2");
    CoffeeHouseApp.applySystemProperties(opts);
    assertThat(System.getProperty("c")).isEqualTo("2");
}