Initializers should be able to access PDP object
it might be helpful if they had access to the PDP object which they were initializing. I could imagine a developer subclassing SimplePDP and SimplePDPFactory to add additional functionality and wanting to tweak that functionality with the initializers.
Default Initializers should directly be accessible
A possibility should be provided so that a single default initializer can be exchanged or accessed (in it must be reconfigured).
Then an addAdditionalInitializers-method should also be provided for custom initializers.