Honestly, because we don't know what the possible keys are, I think `obj.*` and `obj` are the only two things that should be capable of removing an object.

If I have these objects

```
{
  "obj": { "f1": "v1"}
}

{
  "obj": {  "f2": "v2" }
}

{
  "obj": {  "f1": "v1",  "f2": "v2" }
}
```

And `excludes = [ "obj.f1"]` I am left with

```
{
}

{
  "obj": {  "f2": "v2" }
}

{
  "obj": {  "f1": "v1",  "f2": "v2" }
}
```

which could be very weird.