public static CompletionWaiter create(Curator curator, Path barrierPath, String id, Duration waitForAll) {
        return new CuratorCompletionWaiter(curator, barrierPath, id, Clock.systemUTC(), waitForAll);
    }
Implementation of a Barrier that handles the case where more than number of members can call synchronize.
Will wait for some time for all servers to do the operation, but will accept the majority of servers to have
done the operation if it takes longer than a specified amount of time.

@author Vegard Havdal
@author Ulf Lilleengen
zkfacade/src/main/java/com/yahoo/vespa/curator/CuratorCompletionWaiter.java