### Question:
AttributeTypePropertyDefinition extends
    PropertyDefinition<AttributeType> { @Override public void validateValue(AttributeType value) throws PropertyException { ifNull(value); } private  AttributeTypePropertyDefinition(
      AbstractManagedObjectDefinition<?, ?> d, String propertyName,
      EnumSet<PropertyOption> options,
      AdministratorAction adminAction,
      DefaultBehaviorProvider<AttributeType> defaultBehavior); static Builder createBuilder(
      AbstractManagedObjectDefinition<?, ?> d, String propertyName); static boolean isCheckSchema(); static void setCheckSchema(boolean value); @Override R accept(PropertyDefinitionVisitor<R, P> v, P p); @Override R accept(PropertyValueVisitor<R, P> v,
      AttributeType value, P p); @Override int compare(AttributeType o1, AttributeType o2); @Override AttributeType decodeValue(String value); @Override String encodeValue(AttributeType value); @Override void validateValue(AttributeType value);  }### Answer:
@Test public void testValidateValue() { AttributeTypePropertyDefinition.setCheckSchema(true); AttributeTypePropertyDefinition d = createPropertyDefinition(); d.validateValue(DirectoryServer.getAttributeTypeOrNull("cn")); }