Ok, looks like I solved it by providing an overrid...

# announcements

[aaverin]

Ok, looks like I solved it by providing an override:

class MultiMap<K : Any, V> : HashMap<K, MutableList<V>>() {

    override fun getOrDefault(key: Any?, defaultValue: MutableList<V>?): MutableList<V> {
        return super.getOrDefault(key, defaultValue)
    }

    fun put(key: K, value: V) {
        var entries = get(key)

        if (entries == null) {
            entries = mutableListOf<V>()
            put(key, entries)
        }

        entries.add(value)
    }
}