public GifRequestBuilder<ModelType> fitCenter() {
        return transformFrame(glide.getBitmapFitCenter());
    }
Transforms each frame of the GIF using {@link com.bumptech.glide.load.resource.bitmap.FitCenter}.

@see #centerCrop()
@see #transformFrame(BitmapTransformation...)
@see #transformFrame(Transformation[])
@see #transform(Transformation[])

@return This request builder..
core/src/main/java/com/bumptech/glide/GifRequestBuilder.java