@Test
	public void testAsMapSubHeadMap() {
		assertEquals(KeySpan.closed(-2, 2),
			map.subMap(-2L, true, 4L, false).headMap(2L, true).keySpan);
		assertEquals(KeySpan.closed(-2, 2),
			rMap.subMap(2L, true, -4L, false).headMap(-2L, true).keySpan);
	}
This exists to verify behavior in {@link #testAsValuesSubIterator()}
Ghidra/Debug/ProposedUtils/src/test/java/ghidra/util/database/DBCachedObjectStoreTest.java