### Question:
FilePluginManager implements PluginManager { @Override public Map<String, AlertPlugin> findAll() { return pluginMap; } FilePluginManager(String dirPath, String[] whitePrefixes, String[] excludePrefixes); @Override AlertPlugin findOne(String pluginId); @Override Map<String, AlertPlugin> findAll(); @Override void addPlugin(AlertPlugin plugin);  }### Answer:
@Test public void findAll() { assertNotNull(filePluginManager.findAll()); }