Retrieves a list of all unique Users represented within a list of recipients.
A possible use for this method is to retrieve a list of recipients (Users) for an event, and then use the list to determine when all of the recipients have been notified.
@event::getUniquePersons(List recipientList)
(List) recipientList: list of recipients
(List) unique Users within recipients list.
The following example illustrates how to retrieve a list of unique Users from a given list of recipients:
$target = "bsmith"
$target::add("wfuller|Work Email")
$target::add("Operations Group")
$recipients = @event::getUniquePersons($target)