Find View with tag recursively in Kotlin

ViewExt.kt

fun ViewGroup.findViewWithTagRecursively(tag: Any): List<View>? {
    val allViews: MutableList<View> = ArrayList<View>()
    val childCount: Int = this.childCount
    for (i in 0 until childCount) {
        val childView: View = this.getChildAt(i)
        if (childView is ViewGroup) {
            childView.findViewWithTagRecursively(tag)?.let { allViews.addAll(it) }
        } else {
            val tagView: Any? = childView.tag
            if (tagView != null && tagView == tag) allViews.add(childView)
        }
    }
    return allViews
}