No, but you can use an extension method.
public static class ListExtensions
{
public static IEnumerable<T> DoCoolStuff<T>(this List<T> collection)
{
// Do cool stuff
}
}
From MSDN: In your code you invoke the extension method with instance method syntax.
var awesomeList = new List<string>();
var awesomestuff = awesomeList.DoCoolStuff();