@Override
        public String toString() {
            return "default group";
        }

        @Nullable
        @Override
        public OrdinalGroup asOrdinal() {
            return null;
        }

        @Override
        public NodeGroup withOrdinalGroup(OrdinalGroup newOrdinal) {
            return newOrdinal;
        }

        @Override

        return "composite group, entry point: " + isReachableFromEntryPoint() + ", ordinal: " + ordinalGroup + ", groups: " + finalizerGroups;
    }

    @Nullable
    @Override
    public OrdinalGroup asOrdinal() {
        return ordinalGroup.asOrdinal();
    }

    @Override
    public NodeGroup withOrdinalGroup(OrdinalGroup newOrdinal) {
        return new CompositeNodeGroup(reachableFromEntryPoint, newOrdinal, finalizerGroups);
    }

        return "task group " + ordinal;
    }

    @Nullable
    public OrdinalGroup getPrevious() {
        return previous;
    }

    @Nullable
    @Override
    public OrdinalGroup asOrdinal() {
        return this;
    }

    @Override
    public NodeGroup withOrdinalGroup(OrdinalGroup newOrdinal) {
        return newOrdinal;
    }

    @Override