## Flyweight

Use sharing to support large numbers of fine-grained objects efficiently. 

### When to use

* when all of the following are true
 * an application uses a large number of objects
 * storage costs are high because of the sheer quantity of objects
 * most object state can be made extrinsic
 * many groups of objects may be replaced by relatively few shared objects once extrinsic state is removed
 * the application doesn't depend on object identity