text: // Package example defines datastructure and services.
  package main
  
  import (
  	"context"
  	"fmt"
  )
  
  type Args struct {
  	A int
  	B int
  }
  
  type Reply struct {
  	C int
  }
  
  type Arith int
  
  func (t *Arith) Mul(ctx context.Context, args *Args, reply *Reply) error {
  	reply.C = args.A * args.B
  	fmt.Printf("call: %d * %d = %d\n", args.A, args.B, reply.C)
  	return nil
  }
  
  func (t *Arith) Add(ctx context.Context, args *Args, reply *Reply) error {
  	reply.C = args.A + args.B
  	fmt.Printf("call: %d + %d = %d\n", args.A, args.B, reply.C)
  	return nil
  }
  
  func (t *Arith) Say(ctx context.Context, args *string, reply *string) error {
  	*reply = "hello " + *args
  	return nil
  }
  