@Override
    public void pause() {
        clear();
        status = Status.PAUSED;
    }
Cancels the current load if it is in progress, clears any resources held onto by the request and replaces
the loaded resource if the load completed with the placeholder.

<p>
    Cleared requests can be restarted with a subsequent call to {@link #begin()}
</p>

@see #cancel()
core/src/main/java/com/bumptech/glide/request/GenericRequest.java