如何在discord.py重写中检查作者是否为管理员

import discord
from discord.ext import commands

bot = commands.Bot(command_prefix='!')

@bot.event
async def on_ready():
    print('Bot is ready.')

@bot.command()
async def test(ctx):
    if ctx.author.guild_permissions.administrator:
        await ctx.send('You are an administrator.')
    else:
        await ctx.send('You are not an administrator.')

bot.run('YOUR_BOT_TOKEN')