code: func ServiceMethod(m string) (string, string, error) {
  	if len(m) == 0 {
  		return "", "", fmt.Errorf("malformed method name: %q", m)
  	}
  
  	// grpc method
  	if m[0] == '/' {
  		// [ , Foo, Bar]
  		// [ , package.Foo, Bar]
  		// [ , a.package.Foo, Bar]
  		parts := strings.Split(m, "/")
  		if len(parts) != 3 || len(parts[1]) == 0 || len(parts[2]) == 0 {
  			return "", "", fmt.Errorf("malformed method name: %q", m)
  		}
  		service := strings.Split(parts[1], ".")
  		return service[len(service)-1], parts[2], nil
  	}
  
  	// non grpc method
  	parts := strings.Split(m, ".")
  
  	// expect [Foo, Bar]
  	if len(parts) != 2 {
  		return "", "", fmt.Errorf("malformed method name: %q", m)
  	}
  
  	return parts[0], parts[1], nil
  }
docs: // ServiceMethod converts a gRPC method to a Go method
  // Input:
  // Foo.Bar, /Foo/Bar, /package.Foo/Bar, /a.package.Foo/Bar
  // Output:
  // [Foo, Bar]