```vue
<template>
  <sd-group-tree :default-selected-keys="['20000']" @update:selectedKeys="handleTreeSelect" />
</template>

<script>
export default {
  data() {
    return {
      mainSendUnit: [],
    }
  },
  methods: {
    handleTreeSelect(key) {
      console.log(key)
    },
  },
}
</script>
```
