public DrawableRequestBuilder<ModelType> thumbnail(
            DrawableRequestBuilder<?> thumbnailRequest) {
        super.thumbnail(thumbnailRequest);
        return this;
    }
Loads and displays the {@link GlideDrawable} retrieved by the given thumbnail request if it finishes before this
request. Best used for loading thumbnail {@link GlideDrawable}s that are smaller and will be loaded more quickly
than the fullsize {@link GlideDrawable}. There are no guarantees about the order in which the requests will
actually finish. However, if the thumb request completes after the full request, the thumb {@link GlideDrawable}
will never replace the full image.

@see #thumbnail(float)

<p>
    Note - Any options on the main request will not be passed on to the thumbnail request. For example, if
    you want an animation to occur when either the full {@link GlideDrawable} loads or the thumbnail loads,
    you need to call {@link #animate(int)} on both the thumb and the full request. For a simpler thumbnail
    option where these options are applied to the humbnail as well, see {@link #thumbnail(float)}.
</p>

<p>
    Only the thumbnail call on the main request will be obeyed, recursive calls to this method are ignored.
</p>

@param thumbnailRequest The request to use to load the thumbnail.
@return This builder object.
core/src/main/java/com/bumptech/glide/DrawableRequestBuilder.java