title: (discord.py) functions in a cog
body: <p>I've been trying to develop a discord bot in python, and I want to make a bunch of &quot;hidden&quot; commands that don't show up in help. I want to make it so that whenever someone activates a hidden command, the bot sends them a pm. I tried to make a function to do it, but so far it doesn't work. Here is the code in the cog file:</p>
  <pre><code>import discord
  from discord.ext import commands
  
  class Hidden(commands.Cog):
    def __init__(self, client):
      self.client = client
    
    def hidden_message(ctx):
      ctx.author.send('You have found one of several hidden commands! :shushing_face:\nCan you find them all? :thinking:')
  
    @commands.command()
    async def example(self, ctx):
          
      await ctx.send('yes')
  
      hidden_message(ctx)
  
  def setup(client):
    client.add_cog(Hidden(client))
  </code></pre>
  <p>When the example command is run, the bot responds normally, but the function isn't called. There are no error messages in the console. I'm still pretty new to python so could someone tell me what I'm doing wrong?</p>