/guava/android/guava/src/com/google/common/util/concurrent/ExecutionSequencer.java
while ( ( queuedTask = executingTaskQueue.nextTask) != null && ( queuedExecutor = localDelegate) != null) {
while ( ( queuedTask = executingTaskQueue.nextTask ) != null && ( queuedExecutor = executingTaskQueue.nextExecutor ) != null ) {
try { Runnable localTask = requireNonNull(task); task = null; localTask.run(); Runnable queuedTask; Executor queuedExecutor; <extra_id_0> executingTaskQueue.nextTask = null; executingTaskQueue.nextExecutor = null; queuedExecutor.execute(queuedTask); } } finally { executingTaskQueue.thread = null;