how to set protobuf filedName and coment as variables in live template?

I have a protobuf file as follow:

``` test.proto

syntax = "proto3";

package api.test.test;

option go_package = "exmple.com/api/test;test";

message Test {

string code = 1; // stock_code @gotags: gorm:"type:bigint NOT NULL DEFAULT 0 COMMENT 'stock_code';"

string company_name = 2 [json_name = "company_name"];

string filed_name = 3 ; // comment @gotags: gorm:"type:bigint NOT NULL DEFAULT 0 COMMENT 'comment';"

}

```

What I want to do is get `filed_name` and `comment` in line 10 in the test.proto file as live template variables as follow, what should I do?

• 打开设置： File -> Settings -> Editor -> Live Templates -> proto 

• add json template 

   

```template-text

[json_name =  "$FIELD_NAME$"]  $commnet$

```

• click button “Edit Variables…"

  what's the Expression for variable's Name   "FIELD_NAME" and "comment"