code: def service_region(self, service_name):
      
      if not self.services()[service_name].has_key("region"):
        return EFConfig.DEFAULT_REGION
      else:
        return self.services()[service_name]["region"]
docs: Args:
        service_name: the name of the service in the service registry
      Returns:
        the region the service is in, or EFConfig.DEFAULT_REGION if the region was not found