class ActiveFedora::Associations::CollectionAssociation

def ids_reader

Implements the ids reader method, e.g. foo.item_ids for Foo.has_many :items 
def ids_reader
  if loaded?
    load_target.map do |record|
      record.id
    end
  else
    load_from_solr.map do |solr_record|
      solr_record['id']
    end
  end
end