@Test
public void testGetMessageDigestAlgorithmNames() {

OK get the set and check it has some elements
<String> algNames = DigestUtilities.getMessageDigestAlgorithmNames();
Now loop through our enum values and test they're in the set
 (DigestAlgorithm alg : DigestAlgorithm.values()) {
 assertTrue("Java standard name " + alg.getJavaName() + " should be in digest set", algNames.contains(alg.getJavaName()));
}