public function onSaving($event, $payload) {

        // Destructure params
        list($model) = $payload;

        // Check that the model supports uploads through Upchuck
        if (!$this->supportsUploads($model)
            || !($attributes = $model->getUploadAttributes())) return;

        // Loop through the all of the upload attributes ...
        event(new Events\HandlingSaving($model));
        foreach($attributes as $attribute) {

            // Check if there is an uploaded file in the upload attribute
            if (($file = $model->getAttribute($attribute))
                && is_a($file, UploadedFile::class)) {

                // Move the upload and get the new URL
                $url = $this->storage->moveUpload($file);
                $model->setUploadAttribute($attribute, $url);
            }

            // If the attribute field is dirty, delete the old file
            if ($model->isDirty($attribute)
                && !$this->keepsFilesOnDelete($model)
                && ($old = $model->getOriginal($attribute))) {
                $this->storage->delete($old);
            }
        }
        event(new Events\HandledSaving($model));
    }