public void resumeRequests() {
        isPaused = false;
        for (Request request : Util.getSnapshot(requests)) {
            if (!request.isComplete() && !request.isCancelled() && !request.isRunning()) {
                request.begin();
            }
        }
        pendingRequests.clear();
    }
Starts any not yet completed or failed requests.
core/src/main/java/com/bumptech/glide/manager/RequestTracker.java