code: def replicas(self):
          
          params = {
              "f" : "json",
  
          }
          url = self._url + "/replicas"
          return self._get(url, params,
                           securityHandler=self._securityHandler,
                           proxy_url=self._proxy_url,
                           proxy_port=self._proxy_port)
docs: returns all the replicas for a feature service