add item to list
remove and destroy all items
get item by index
find child index for item, return -1 if not found
find child index for item by id, return -1 if not found
add item to list
get item by index
remove item from list, return removed item
Replace item with another value, destroy old value.
Replace item with another value, destroy old value.
returns count of items
object list holder, owning its objects - on destroy of holder, all own objects will be destroyed