This example makes use of IFindUsersProcessor to filter a list of UserData users.
When dealing with objects it is a good practice to set the RfDropDownMulti.ItemComparer parameter.
The RfDropDownMulti uses this to determine if an item within RfDropDownMulti.Items is selected.
By default the ItemComparer is set to:
(i1, i2) => i1?.Equals(i2)
The only time the ItemComparer does not have to be set with an object is when the list of options
stays the same. That would then allow the equals reference check to come back as true.