Hmm! I have to return `Map<String, String?>`...

# getting-started

[henrik]

Hmm! I have to return Map<String, String?> instead of Map<String, String> here. How can I make it return Map<String, String>?

fun blah() : Map<String, String> {
    return mapOf("a" to null, "b" to "foo").filter{ it.value != null }
}