extension.kt

fun <K, V: Any> Map<K, V?>.filterValuesNotNull(): Map<K, V> {
    val map = HashMap(this)
    val result = LinkedHashMap<K, V>()
    for (entry in map) {
        if (entry.value != null) {
            result[entry.key] = entry.value
        }
    }
    return result
}