@Test
public void testNodes() throws IOException {

  File tmp = FileUtil.createTempFile("test-flume", "");
  tmp.delete();
  tmp.deleteOnExit();
  MemoryBackedConfigStore store = new MemoryBackedConfigStore();
  ConfigManager manager = new ConfigManager(store);
  manager.addLogicalNode("physical", "logical1");
  manager.addLogicalNode("physical", "logical2");
  manager.addLogicalNode("physical", "logical3");
  manager.addLogicalNode("p2", "l2");
  manager.addLogicalNode("p3", "l3");
  List<String> lns = manager.getLogicalNode("physical");
  assertTrue(lns.contains("logical1"));
  assertTrue(lns.contains("logical2"));
  assertTrue(lns.contains("logical3"));
  assertTrue(manager.getLogicalNode("p2").contains("l2"));
  assertTrue(manager.getLogicalNode("p3").contains("l3"));
}