docs: function (selector, property, expected, hash) {
      this.actionQueue.push(this.webdriverClient.element.bind(this.webdriverClient, selector));
      this.actionQueue.push(this.webdriverClient.cssProperty.bind(this.webdriverClient, property));
      this.actionQueue.push(this._cssCb.bind(this, selector, property, hash, expected));
      return this;
    }