### Question:
EnvironmentConfigSource implements ConfigSource { @Override public Map<String, String> getProperties() { return getEnv(); }  @Override Map<String, String> getProperties(); @Override int getOrdinal(); @Override String getValue(String propertyName); @Override String getName();  }### Answer:
@Test public void testGetProperties() { Map<String,String> env = System.getenv(); assertEquals(env, source.getProperties()); for (String string : env.keySet()) { assertEquals(env.get(string), source.getValue(string)); } }