For the same reasons as
LOG4J2-891 was raised, equals() and hashCode() should be removed from AbstractFilter.
Similar to the approach for AbstractFilter I will keep the existing implementation of equals() and rename it equalsImpl() (with the call to super.equals(obj) replaced by super.equalsImpl(obj)).
Similarly for hashCode() to hashCodeImpl(). The xxxImpl() methods will be protected, similar to the approach taken in AbstractFilter.