why do AbstractPolicy constructors not have PolicyMetaData argument?

Hi,

I wonder why AbstractPolicy constructors do not have PolicyMetaData argument but PolicyReference constructor contains it? It looks like odd and not consistent.
The following is the existing AbstractPolicy constructor.

    protected AbstractPolicy(URI id, String version,
                             CombiningAlgorithm combiningAlg,
                             String description, Target target,
                             String defaultVersion, Set obligations,
                             List parameters) 


Best Regard
Hao