public BitmapRequestBuilder<ModelType, TranscodeType> thumbnail(BitmapRequestBuilder<?, TranscodeType>
            thumbnailRequest) {
        super.thumbnail(thumbnailRequest);
        return this;
    }
Loads and displays the {@link Bitmap} retrieved by the given thumbnail request if it finishes
before this request. Best used for loading thumbnail {@link Bitmap}s that are smaller and will be loaded more
quickly than the fullsize {@link Bitmap}. 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 Bitmap} 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 Bitmap} 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 request builder.
core/src/main/java/com/bumptech/glide/BitmapRequestBuilder.java