onMapSharedElementsBody.java

@Override
public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {
    if (!mSharedElementViews.isEmpty()) {
        removeObsoleteElements(names, sharedElements, mapObsoleteElements(names));
        for (View sharedElementView : mSharedElementViews) {
            String transitionName = ViewCompat.getTransitionName(sharedElementView);
            names.add(transitionName);
            sharedElements.put(transitionName, sharedElementView);
        }
    }
}