This builds the array for the $pk for all of these methods inside this class.
The primaryKey comes primarily from the REST API.
admin/object/news/1
admin/objects?uri=news/1/2
where
admin/object/news/
admin/objects?uri=news/
is this ID.
1/2/3 => array( array(id =>1),array(id =>2),array(id =>3) )
1 => array(array(id => 1))
idFooBar => array( id => "idFooBar")
idFoo/Bar => array(array(id => idFoo), array(id2 => "Bar"))
1,45/2,45 => array(array(id => 1, pid = 45), array(id => 2, pid=>45))