idFor(name) {
    const key = Symbol.for(name)
    let val = this.#tracked.get(key)
    if (val === undefined) {
      val = 0
    } else {
      val += 1
    }
    this.#tracked.set(key, val)
    return val
  }
Get the next available identifier for the provided `name`.

@param {string} name The label to get an id for.

@returns {number} The id.