@Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            NotFromGroupCheck that = (NotFromGroupCheck) o;
            return this.groupName.equals(that.groupName);
        }
Contains the standard {@link MetaStackElement}s provided by LuckPerms.
common/src/main/java/me/lucko/luckperms/common/cacheddata/metastack/StandardStackElements.java