I'm wondering if it's possible to give a Type to something "empty" in Scala?

For example, I'm looking for something like `Null[String]` or `Nothing[String]` or `None[String]`.

I'm not looking to use an Option. To be honest, what I'm doing is I have a map:

```
options: Map[String, Any] = Map("id" -> Null, "num" -> Null)

```

That other people will "extend" with:

```
_options: Map[String, Any] = Map("id" -> "Hi", "num" -> 5)
options = options ++ _options

```

And I want to be able to specify what types are suppose to be given in the map.

Thanks!