old_contents: import aiohttp
  from lifesaver.bot import Bot
  
  
  class Dogbot(Bot):
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.session = aiohttp.ClientSession(loop=self.loop)
          self.load_all()
  
  
new_contents: import aiohttp
  import discord
  from discord.ext.commands import is_owner
  from lifesaver.bot import Bot, command, Context
  from lifesaver.bot.storage import AsyncJSONStorage
  
  
  class Dogbot(Bot):
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.session = aiohttp.ClientSession(loop=self.loop)
          self.load_all()
          self.add_command(self.blacklist)
          self.add_command(self.unblacklist)
          self.blocked = AsyncJSONStorage('blacklisted_users.json', loop=self.loop)
  
      async def on_message(self, message: discord.Message):
          if str(message.author.id) in self.blocked.all():
              return
          await super().on_message(message)
  
      @command(hidden=True)
      @is_owner()
      async def blacklist(self, ctx: Context, user: discord.User, *, reason=None):
          """Blacklist someone from using the bot."""
          await self.blocked.put(user.id, reason)
          await ctx.ok()
  
      @command(hidden=True)
      @is_owner()
      async def unblacklist(self, ctx: Context, user: discord.User):
          """Unblacklist someone from using the bot."""
          try:
              await self.blocked.delete(user.id)
          except KeyError:
              pass
          await ctx.ok()
  
subject: add user blacklisting