deleteRule(name) {
    const rule = typeof name === 'object' ? name : this.rules.get(name)

    if (
      !rule ||
      // Style sheet was created without link: true and attached, in this case we
      // won't be able to remove the CSS rule from the DOM.
      (this.attached && !rule.renderable)
    ) {
      return false
    }

    this.rules.remove(rule)

    if (this.attached && rule.renderable && this.renderer) {
      return this.renderer.deleteRule(rule.renderable)
    }

    return true
  }
Delete a rule by name.
Returns `true`: if rule has been deleted from the DOM.