There is a suspicious unused method attribute "alphaNodeHashingThreshold" in CompositeObjectSinkAdapter. See this [1]. It can be a potential bug, because as you can see in the previous method in the class, the method is called with "0" as a parameter value for this.

[1] https://github.com/kiegroup/drools/blob/38b68002a9cff5aeada9420cf87362a7b1213900/drools-core/src/main/java/org/drools/core/reteoo/CompositeObjectSinkAdapter.java#L104