discord.py中是否存在角色分配/删除事件？

import discord
from discord.ext import commands

intents = discord.Intents.default()
intents.members = True

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

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

@bot.event
async def on_member_update(before, after):
    if len(before.roles) < len(after.roles):
        added_role = next(role for role in after.roles if role not in before.roles)
        print(f'{after.name} was assigned the role {added_role.name}.')
    elif len(before.roles) > len(after.roles):
        removed_role = next(role for role in before.roles if role not in after.roles)
        print(f'{after.name} had the role {removed_role.name} removed.')

bot.run('YOUR_BOT_TOKEN')