ASP.NET AJAX :IExtenderControl Interface

The IExtenderControl interface defines the contract of an extender
control. It comprises two methods: GetScriptDescriptors and
GetScriptReferences. Here's the definition of the interface:

public interface IExtenderControl
{
IEnumerable<ScriptDescriptor> GetScriptDescriptors(
Control targetControl);
IEnumerable<ScriptReference> GetScriptReferences();
}