Currently this is used as a default value for suppressedException:

    // Setting this static field introduces an acceptable
    // initialization dependency on a few java.util classes.
    private static final List<Throwable> SUPPRESSED_SENTINEL =
        Collections.unmodifiableList(new ArrayList<Throwable>(0));

Substituting Collections.unmodifiableList(new ArrayList<Throwable>(0)) with Collections.emptyList() indicate 3 fewer classes are loaded in a hello world program, and thus a very small startup footprint improvement.

emptyList should be providing the same immutability and identity requirements.