All service types packaged in a ADF Library jar must implement this method of
type and instance discovery to expose the packaged components.
For the strategy constructor you have 2 options:
Either a default no argument constructor, or if you're interested in using
the DescriptorContext before getResources then you can implement the
constructor that takes a instance of the context. One reason might be if you
plan to use the manifest or other metadata locations for display name
overrides. Visibility data is not to be processed here. You must return all
descriptors without filtering. That's done by the various display methods.
For example: the resource catalog palette, the data control palette, etc.