Kerb5Authenticator auth = new Kerb5Authenticator((Subject) null);
        SmbUnsupportedOperationException ex = assertThrows(SmbUnsupportedOperationException.class, auth::refresh);
        assertTrue(ex.getMessage().contains("Refreshing credentials is not supported"));
    }

    @Test
    @DisplayName("clone: copies all relevant fields")
    void clone_copiesFields() {
        Subject subj = new Subject();

            Subject copySubj = copy.getSubject();
            assertNotNull(copySubj);
            assertSame(cachedOrig, copySubj, "Clone should share the cached Subject reference");

            // Refreshing the original must not clear the clone's cached subject
            orig.refresh();
            // Clone should retain its cached Subject

    }

    @Override
    public void refresh() throws CIFSException {
        // custom Kerb5Authenticators need to override this method for support
        throw new SmbUnsupportedOperationException("Refreshing credentials is not supported by this authenticator");
    }

    @Override
    public Kerb5Authenticator clone() {
        Kerb5Authenticator auth = new Kerb5Authenticator(getSubject());

	dm1 := NewDRWMutex(ds, "aap")
	dm2 := NewDRWMutex(ds, "noot")

	dm1.Lock(id, source)
	dm2.Lock(id, source)
	dm1.Unlock(t.Context())
	dm2.Unlock(t.Context())
}

// Test refreshing lock - refresh should always return true
func TestSuccessfulLockRefresh(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	dm := NewDRWMutex(ds, "aap")

				lockRefreshed++
			} else {
				lockNotFound++
			}
			if lockRefreshed >= quorum || lockNotFound > len(restClnts)-quorum {
				done = true
			}
		case <-ctx.Done():
			// Refreshing is canceled
			return false, ctx.Err()
		}
		if done {
			break
		}
	}

	// We may have some unused results in ch, release them async.
	go func() {
		wg.Wait()
		xioutil.SafeClose(ch)