Affects Version/s: None
Fix Version/s: 2.0
GenericKeyedObjectPool.clear() registers the key, and then checks if the objectDeque obtained by using the key is null.
Since register creates the key entry in poolMap, the retrieved value should never be null.
If it is nullm then AFAICT that is a code bug, which should be reported rather than ignored.
[If it were possible for the key to be null, then the same null check should be added to the private destroy method.]
Also, register returns the ObjectDeque, so the clear() code could be simplified; rather than
the method could use:
Similarly for the private destroy method.