如何在discord.py中合并2个on_message函数

import discord
from discord.ext import commands

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

@bot.event
async def on_message(message):
    # 原始的on_message函数1的代码
    if message.content.startswith('hello'):
        await message.channel.send('Hello!')

@bot.event
async def on_message(message):
    # 原始的on_message函数2的代码
    if message.content.startswith('ping'):
        await message.channel.send('Pong!')

# 合并两个on_message函数
@bot.event
async def merged_on_message(message):
    if message.content.startswith('hello'):
        await message.channel.send('Hello!')
    if message.content.startswith('ping'):
        await message.channel.send('Pong!')

bot.run('YOUR_BOT_TOKEN')