public GifTypeRequest<ModelType> asGif() {
        return optionsApplier.apply(new GifTypeRequest<ModelType>(this, streamModelLoader, optionsApplier));
    }
Attempts to always load the resource as a {@link com.bumptech.glide.load.resource.gif.GifDrawable}.
<p>
    If the underlying data is not a GIF, this will fail. As a result, this should only be used if the model
    represents an animated GIF and the caller wants to interact with the GIfDrawable directly. Normally using
    just an {@link DrawableTypeRequest} is sufficient because it will determine whether or
    not the given data represents an animated GIF and return the appropriate animated or not animated
    {@link android.graphics.drawable.Drawable} automatically.
</p>

@return A new request builder for loading a {@link com.bumptech.glide.load.resource.gif.GifDrawable}.
core/src/main/java/com/bumptech/glide/DrawableTypeRequest.java