Question: keys with the same name

Hi
Is there a way to avoid writing big map objects by excluding keys with same name in source and dest?
 eg 
```
const  source ={
foo: 1,
bar:2,
baz:3
}

const dest = {
foo : null,
bar: null,
x: null,
y: null
}

```

My expectation is an empty map object would return a dest object with keys foo and bar

Thanks
