NOJIRA There is a bug in PHP 5.3.x that prevents us from using this definition.

The resulting error is: Can't inherit abstract function IAttributeValue::getType() (previously declared abstract in AttributeValue). There is an abstract function getType() here and the same thing is defined in the Interface. The AttributeValue implementations inherit from this class and implement the Interface, which makes PHP versions prior to 5.3.9 barf (even though it shouldn't). It's fixed in 5.3.9+. The widely used RHEL/CentOS 6.5 (latest version as of July 2014) still uses PHP 5.3.3 though, so we uncomment this for now. The interface still requires AttributeValue implementations to implement this method so we should be okay.