code: def default_package(self):
          
          packages = [pk for pk in self.packages() 
                          if pk.get('default') == 'true']
          if packages:
              return packages[0]
          else:
              return None
docs: ::
          
              GET /:login/packages
          
          :Returns: the default package for this datacenter
          :rtype: :py:class:`dict` or ``None``
          
          Requests all the packages in this datacenter, filters for the default, 
          and returns the corresponding dict, if a default has been defined.