parameter TaskName = "PurgeTaskHistory";
This defines the user-visible name of this task;
This is defined in subclasses.
# of Log History Days to keep not including current day, minimum value is 1
This method is responsible for executing the task.
At the scheduled time, the Task Manager creates an instance of this object,
sets any property values using the stored "settings" for the task, and then
invokes this method to execute the task.
In order to execute a real task, override this method in a subclass.