Creates a new System.Web.UI.ControlCollection object to hold the child controls (both literal and server) of the server control.
A System.Web.UI.ControlCollection object to contain the current server control's child server controls.
Override this method in a custom server control if you have created a collection object that is derived from the System.Web.UI.ControlCollection class. You can then instantiate that collection class in the override of this method.