Run pool maintenance. Evict objects qualifying for eviction and then ensure that the minimum number of idle instances are available. Since the Timer that invokes Evictors is shared for all Pools but pools may exist in different class loaders, the Evictor ensures that any actions taken are under the class loader of the factory associated with the pool.
The idle object evictor {@link TimerTask}.
@see GenericKeyedObjectPool#setTimeBetweenEvictionRunsMillis