### Question:
Parameters extends Static { public static boolean isValid(final ParameterValue<?> value) { return isValidValue(value.getDescriptor(), value.getValue(), false) == null; } private  Parameters(); static boolean isValid(final ParameterValue<?> value); static ConformanceResult isValid(final GeneralParameterValue value,
            final GeneralParameterDescriptor descriptor); @Deprecated static ParameterValue<?> getOrCreate(final ParameterDescriptor<?> parameter,
            final ParameterValueGroup group); static List<GeneralParameterValue> search(final GeneralParameterValue parameter,
            final String name, int maxDepth); static void copy(final GeneralParameterValue parameters, final Map<? super String, Object> destination); @Deprecated static boolean ensureSet(final ParameterValueGroup parameters, final String name,
            final double value, final Unit<?> unit, boolean force); static Map<String,Object> toMap(final ParameterValueGroup source); static ParameterValueGroup toParameter(final Map<String, ?> params, final ParameterDescriptorGroup desc); static ParameterValueGroup toParameter(final Map<String, ?> params,
                                                  final ParameterDescriptorGroup desc, final boolean checkMandatory); static GeneralParameterValue getParameterOrGroup(ParameterValueGroup group,String name); @Deprecated
    static final ParameterDescriptorGroup EMPTY_GROUP; }### Answer:
@Test public void testIsValid() { final ParameterDescriptorGroup group = create("Group", create("Test1", 10, 5, 15), new DefaultParameterDescriptor<Integer>(Collections.singletonMap(NAME_KEY, "Test2"), 1, 1, Integer.class, null, new Integer[] {1, 4, 8}, 4)); ParameterDescriptorGroup lenient = create("Lenient", create("Test1", 10, 0, 100), create("Test2", 8, 0, 100)); ParameterValueGroup values = lenient.createValue(); ConformanceResult result = Parameters.isValid(values, group); assertTrue("Default values should pass the test.", result.pass()); values.parameter("Test2").setValue(0); result = Parameters.isValid(values, group); assertFalse(result.pass()); assertTrue("The error message should contains the name of the invalid parameter.", result.getExplanation().toString().contains("Test2")); values.parameter("Test2").setValue(null); result = Parameters.isValid(values, group); assertTrue(result.pass()); lenient = create("Lenient", create("Test2", 8, 0, 100)); values = lenient.createValue(); result = Parameters.isValid(values, group); assertFalse(result.pass()); assertTrue("The error message should contains the name of the missing parameter.", result.getExplanation().toString().contains("Test1")); lenient = create("Lenient", create("Test1", 10, 0, 100), create("Test2", 8, 0, 100), create("Test3", 0, 0, 100)); values = lenient.createValue(); result = Parameters.isValid(values, group); assertFalse(result.pass()); assertTrue("The error message should contains the name of the extra parameter.", result.getExplanation().toString().contains("Test3")); }