ViewModel.java

@MainThread
final void clear() {
    mCleared = true;
    // Since clear() is final, this method is still called on mock 
    // objects and in those cases, mBagOfTags is null. It'll always 
    // be empty though because setTagIfAbsent and getTag are not 
    // final so we can skip clearing it
    if (mBagOfTags != null) {
        for (Object value : mBagOfTags.values()) {
            // see comment for the similar call in setTagIfAbsent
            closeWithRuntimeException(value);
        }
    }
    onCleared();
}