Clears any objects sitting idle in the pool, releasing any associated
resources (optional operation). Idle objects cleared must be
{@link PooledObjectFactory#destroyObject(PooledObject)}.
@throws UnsupportedOperationException
if this implementation does not support the operation
Clears any objects sitting idle in the pool, releasing any associated resources (optional operation). Idle objects cleared must be {@link PooledObjectFactory#destroyObject(PooledObject)}.
@throws UnsupportedOperationException if this implementation does not support the operation
@throws Exception if the pool cannot be cleared