grpc_handle_attr_initialize_np - Initializes function handle attributes.
  grpc_error_t grpc_handle_attr_initialize_np(grpc_handle_attr_t_np *attr)
  grpc_handle_attr_t_np *attrThe grpc_handle_attr_initialize_np() function initializes function handle attributes.
This function is MT-safe.
If successful, GRPC_NO_ERROR is returned. In the case of an error, Error code is returned.
  GRPC_NOT_INITIALIZED  GRPC_OTHER_ERROR_CODE