shadows/framework/src/main/java/org/robolectric/android/util/concurrent/PausedExecutorService.java
public boolean runNext() {
    if (!hasQueuedTasks()) {
      return false;
    }
    if (Thread.currentThread().equals(executorThread)) {
      Logger.info("ignoring request to execute task - called from executor's own thread");
      return false;
    }
    Runnable task = deferredTasks.poll();
    task.run();
    return true;
  }
public boolean runNext() {
    if (!hasQueuedTasks()) {
      return false;
    }
    if (Thread.currentThread().equals(executorThread)) {
      Logger.info("ignoring request to execute task - called from executor's own thread");
      return false;
    }
    Runnable task = deferredTasks.poll();
    task.run();
    return true;
  }
Executes the next queued task.

Will be ignored if called from the executor service thread to prevent deadlocks.

@return true if task was run, false if queue was empty