public V removeValue(K key, int index) {
        List<V> list = map.get(key);
        if (list != null)
            return list.remove(index);
        else
            throw new IndexOutOfBoundsException("The list at '" + key + "' is empty");
    }
Removes the value at the given index.

@return the removed value
@throws IndexOutOfBoundsException if there is no value at the given index for this key
vespajlib/src/main/java/com/yahoo/collections/ListMap.java