@Override
        protected Drawable doInBackground(String... params) {
            source = params[0];

            if (resources.get() != null) {
                if (compressImage) {
                    return fetchCompressedDrawable(resources.get(), source);
                } else {
                    return fetchDrawable(resources.get(), source);
                }
            }

            return null;
        }
Static inner {@link AsyncTask} that keeps a {@link WeakReference} to the {@link UrlDrawable}
and {@link HtmlHttpImageGetter}.
<p/>
This way, if the AsyncTask has a longer life span than the UrlDrawable,
we won't leak the UrlDrawable or the HtmlRemoteImageGetter.
android/modules/module_common/src/main/java/github/tornaco/android/thanos/widget/html/HtmlHttpImageGetter.java