grpc_call_arg_stack_async - Executes an RPC.
  int grpc_call_arg_stack_async(grpc_function_handle_t *handle,
                                grpc_arg_stack_t *stack)
  grpc_function_handle_t *handle  grpc_arg_stack_t *stackThe grpc_call_arg_stack_async() function calls the function defined by function handle. The grpc_call_arg_stack_async() function does not wait for the execution of the called function to complete.
This function is MT-safe.
If successful, the session ID is returned. In the case of an error, -1 is returned.
  GRPC_NOT_INITIALIZED  GRPC_OTHER_ERROR_CODE