code: def get_items(self):
          
          from .layers import Layer
  
          # no expansion support, just URLs
          results = []
          for url in self.items:
              if '/layers/' in url:
                  r = self._client.request('GET', url)
                  results.append(self._client.get_manager(Layer).create_from_result(r.json()))
              else:
                  raise NotImplementedError("No support for %s" % url)
          return results
docs: Return the item models associated with this Publish group.