How would i get a proper Key Value in this component:

```
 {var.map((building, index) => {
        const handles = building.buildingVertices.map((point) => {
          return (
            <DrawingHandle
              key={`${index}_handle${point.id}`}
            />
          )
        })
        return (
          <>{handles}</> //<--- how do i get a key in here?
        )
      })}

```

since `<>{handles}</>` does not have a key value, i get the error: `Warning: Each child in a list should have a unique "key" prop.`

Thanks a lot!