This package contains implementations of the {@link org.apache.commons.collections.Bag Bag} and {@link org.apache.commons.collections.SortedBag SortedBag} interfaces. A bag stores an object and a count of the number of occurences of the object.

The following implementations are provided in the package:

- HashBag - implementation that uses a HashMap to store the data
- TreeBag - implementation that uses a TreeMap to store the data

The following decorators are provided in the package:

- Synchronized - synchronizes method access for multi-threaded environments
- Unmodifiable - ensures the bag cannot be altered
- Predicated - ensures that only elements that are valid according to a predicate can be added
- Typed - ensures that only elements that are of a specific type can be added
- Transformed - transforms each element added to the bag