json/call.go
func CallPeer(ctx Context, peer *tchannel.Peer, serviceName, method string, arg, resp interface{}) error {
	call, err := peer.BeginCall(ctx, serviceName, method, &tchannel.CallOptions{Format: tchannel.JSON})
	if err != nil {
		return err
	}

	return wrapCall(ctx, call, method, arg, resp)
}
func CallPeer(ctx Context, peer *tchannel.Peer, serviceName, method string, arg, resp interface{}) error {
	call, err := peer.BeginCall(ctx, serviceName, method, &tchannel.CallOptions{Format: tchannel.JSON})
	if err != nil {
		return err
	}

	return wrapCall(ctx, call, method, arg, resp)
}
// CallPeer makes a JSON call using the given peer.