I have resource `Draft` which has the following representation:

```
{
   "name": "name",
   "groups": ["group1", "group2"] 
}

```

I need to design endpoint which would allow to add new groups to `groups`. 

For instance, lets say client wants to modify the resource above by adding two new groups: group3 and group4, then, after this operation, the resource should look like:

```
{
   "name": "name",
   "groups": ["group1", "group2", "grpoup3", "group4"] 
}

```

I'm not sure what should be the right URL structure and HTTP method for such operation.

Currently I'm considering the following option:

```
PATCH `/draft/groups/add` 

{
    'groups': ["group3", "group4"]
}

```

However, I'm not quite sure if that's the right choice.

Any help would be appreciated, 

Thanks