code: def url(self, name):
          
          name = urllib.quote_plus(self._clean_name(name), safe='/')
  
          if self.bucket_cname:
              return "http://%s/%s" % (self.bucket_cname, name)
          elif self.host:
              return "http://%s/%s/%s" % (self.host, self.bucket_name, name)
          # No host ? Then it's the default region
          return "http://s3.amazonaws.com/%s/%s" % (self.bucket_name, name)
docs: Since we assume all public storage with no authorization keys, we can
          just simply dump out a URL rather than having to query S3 for new keys.