@Test
	public void testAsKeySetDescendingSet() {
		assertEquals(Direction.BACKWARD, keySet.descendingSet().direction);
		assertEquals(Direction.FORWARD, keySet.descendingSet().descendingSet().direction);
	}
This exists to verify behavior in {@link #testAsValuesSubIterator()}
Ghidra/Debug/ProposedUtils/src/test/java/ghidra/util/database/DBCachedObjectStoreTest.java