+
+ assertThatThrownBy(() -> keyUse.setKey(null)).hasMessageMatching("^key is marked .*on.*ull but is null$");
+
+ assertThatThrownBy(() -> keyUse.getCompatibility(null)).hasMessageMatching(OTHER_KEY_IS_NULL);
+
+ assertThatThrownBy(() -> keyUse.isCompatible(null)).hasMessageMatching(OTHER_KEY_IS_NULL);
+
+ assertThatThrownBy(() -> keyUse.validate(null)).hasMessageMatching("^result is marked .*on.*ull but is null$");
+
+ PfKeyUse testKeyUse = new PfKeyUse(new DummyPfConceptKeySub(new PfConceptKey()));
+ assertEquals(testKeyUse, new PfKeyUse(testKeyUse));
+
+ assertThatThrownBy(() -> new PfKeyUse((PfKeyUse) null)).isInstanceOf(NullPointerException.class);
+
+ assertThatThrownBy(() -> keyUse.isNewerThan(null)).hasMessageMatching(OTHER_KEY_IS_NULL);
+
+ assertEquals(false, testKeyUse.isNewerThan(keyUse));
+ assertEquals(false, testKeyUse.isNewerThan(testKeyUse));
+
+ assertEquals(0, testKeyUse.getMajorVersion());
+ assertEquals(0, testKeyUse.getMinorVersion());
+ assertEquals(0, testKeyUse.getPatchVersion());