Get the Unit List for a Training Class. 

This is a listing of all Units for a single Class (or Instance item). 

Each Unit is represented by a TUnit. The collection of Units is represented by a List of TUnit. 

A token is passed for authentication. If the authentication fails, or other errors occur, no units are returned. The result of the authentication is represented by a TAuthenticate object. 

Requires a valid registration key entry for the Short Courses feature. 

This function has security level "Unrestricted", and can be accessed by any authenticated user.

[WebMethod(Description = "Gets a list of units within a class (instance)")]
public TAuthUnitList GetUnitsForClass(string sToken, int iInst_ID);