CollectionTally
 CollectionTally counts (tallies) the number of occurrences
            of each object in one or more enumerations.
                
The result of a  CollectionTally.
The result of the comparison between the two collections.
Construct a CollectionTally object from a comparer and a collection.
Try to remove an object from the tally.
Try to remove a set of objects from the tally.