splice<T> function
Implementation
List<T> splice<T>(List<T> list, int index,
[num howMany = 0, /*<T | List<T>>*/ elements]) {
var endIndex = index + howMany.truncate();
list.removeRange(index, endIndex >= list.length ? list.length : endIndex);
if (elements != null) {
list.insertAll(index, elements is List<T> ? elements : <T>[elements]);
}
return list;
}