async save(tier) {
        if (this.#ids[tier.id.toHexString()]) {
            const existing = this.#store.findIndex((item) => {
                return item.id.equals(tier.id);
            });
            this.#store.splice(existing, 1, tier);
        } else {
            this.#store.push(tier);
            this.#ids[tier.id.toHexString()] = true;
        }
    }
@param {Tier} linkClick
@returns {Promise<void>}