_clear() {
    const local = this.localStorage();
    const itemRe = new RegExp(`^${this.name}-`);

    // Remove id-tracking item (e.g., "foo").
    local.removeItem(this.name);

    // Match all data items (e.g., "foo-ID") and remove.
    for (let k in local) {
      if (itemRe.test(k)) {
        local.removeItem(k);
      }
    }

    this.records.length = 0;
  }
Clear localStorage for a collection
@returns {undefined}