Package member

APP establishes uses the term of members to describe
resources within an APP service context.

APP says:
'''
A resource whose IRI is listed in a Collection by a link
element with a relation of "edit" or "edit-media". 
'''

The base member is the what amplee calls the EntryMember
which is the resource whose IRI is contained in the
link defined by rel="edit".

The EntryMember should be rarerly used directly has it is
only meaningful if your resource is an Atom entry document.

On the other hand the MediaMember describes the resource
whose IRI is contained in the link defined by rel="edit-media".

The Mediamember will certainly be the most common class to
inherit for your own member implementations.