@GwtIncompatible("NullPointerTester")
public void testNullPointers() throws Exception {
NullPointerTester tester = new NullPointerTester();
tester.setDefault(Comparable[].class, new Comparable[] { 0 });
tester.testAllPublicStaticMethods(ImmutableSortedSet.class);
}
public void testEmpty_comparator() {
SortedSet<String> set = of();
assertSame(Ordering.natural(), set.comparator());