I compile the following to javascript: ``` cons...

# javascript

[hallvard]

I compile the following to javascript:

constructor(map: Map<String, Any?>) {
        if (map.isEmpty()) {
            throw IllegalArgumentException("Cannot construct Message object from empty map.")
        }
        backing = map
    }

... and get this in the console:

TypeError: map.isEmpty is not a function

Did I miss something obvious?