code: def defaults(self, *args):
          
          ns = self.Namespace
          ns.obj = self.obj
  
          def by(source, *ar):
              for i, prop in enumerate(source):
                  if prop not in ns.obj:
                      ns.obj[prop] = source[prop]
  
          _.each(args, by)
  
          return self._wrap(ns.obj)
docs: Fill in a given object with default properties.