static public void SetChildrenAtSelf <T>(this Component item, IEnumerable <T> children) where T : Component
{
item.DestroyChildren();
item.AddChildrenAtSelf(children);
}
static public void SetChildrenAtSelf(this Component item, IEnumerable <GameObject> children)
{
item.DestroyChildren();
item.AddChildrenAtSelf(children);
}