/guava/android/guava/src/com/google/common/util/concurrent/ServiceManager.java
listeners.addListener( executor) ;
listeners.addListener ( listener, executor ) ;
} } finally { monitor.leave(); } } void addListener(Listener listener, Executor executor) { <extra_id_0> } void awaitHealthy() { monitor.enterWhenUninterruptibly(awaitHealthGuard); try { checkHealthy(); } finally {