Deletes units from an enrolment. 

An Enrolment ID (enrolmentId) is passed as a parameter. This should be the ID of a client enrolment. This can be sourced from functions such as GetEnrolmentsForClient or GetEnrolmentsForOccurrence. 

The parameter unitCodes is a List of strings, indicating the codes of the units to delete from the enrolment. This can be obtained using function such as GetUnitsForEnrolment. 

The reason parameter will be recorded in the deletion log. 

An error will occur if any units specified do not exist on the enrolment. An error will occur if any units specified have any result (other than Not Yet Started). 

A token is passed for authentication. If the authentication fails, or other errors occur, no units are deleted. 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 "Protected", and can only be accessed by users that have explicitly been granted permission to the API.

[WebMethod(Description = "Deletes the specified units from the existing enrolment ID")]
public TAuthenticate DeleteUnitsFromEnrolment(string token, int enrolmentId, List<string> unitCodes, string reason);