concurrent/src/main/java/io/airlift/concurrent/MoreFutures.java
public static <T> T getDone(Future<T> future)
    {
        requireNonNull(future, "future is null");
        checkArgument(future.isDone(), "future not done yet");
        return getFutureValue(future);
    }
public static <T> T getDone(Future<T> future)
    {
        requireNonNull(future, "future is null");
        checkArgument(future.isDone(), "future not done yet");
        return getFutureValue(future);
    }
Returns the result of the input {@link Future}, which must have already completed.
<p>
Similar to Futures{@link Futures#getDone(Future)}, but does not throw checked exceptions.