Callable and Future

Suppose that you want to count the number of occurrences of a word in a large file. Since the operation can take a very long time, you decide to do it asynchronously in order to prevent blocking the main thread of the application.

You have the following code:

ExecutorService executor = Executors.newSingleThreadExecutor();
Callable<Integer> countWordsInFile = () -> {
    int wordCount = 0;
    // accessing a file and calculating wordCount
    return wordCount;
};
Future<Integer> task = executor.submit(countWordsInFile);

// some other statements here
TimeUnit.SECONDS.sleep(15);

int count = task.get();

What may happen when invoking get method of task (the last line)?

Select all possible cases.