@Test
public void test_getColumnFamilies_firewalling() {

	// passing null collection should return back an empty map
	RangerAuthorizationCoprocessor _coprocessor = new RangerAuthorizationCoprocessor();
	Map<String, Set<String>> result = _coprocessor.getColumnFamilies(null);
	assertNotNull(result);
	assertTrue(result.isEmpty());
	// same for passing in an empty collection
/		result = _coprocessor.getColumnFamilies(new HashMap<byte[], ? extends Collection<?>>());
}