如何在Polymer代码中打开来自父模板的模板中的抽屉？

static get properties() {
  return {
    drawerOpened: {
      type: Boolean,
      value: false
    }
  };
}

<iron-selector selected="{{drawerOpened}}">
  <!-- 抽屉内容 -->
</iron-selector>

<button on-click="openDrawer">打开抽屉</button>

openDrawer() {
  this.drawerOpened = true;
}

<template is="dom-if" if="{{drawerOpened}}">
  <!-- 抽屉内容 -->
</template>