title: discord py - error handling with on_command_error
body: <p>I need help with the error handling in discord.py. I want to send the server owner a private message if my bot doesn't have enough rights for a command or if my bots fail something (reason not enough rights) with the right, that he needs.</p>
  <p>Now I searched a lot and can't find a good example that shows this. I know how to send the Owner a private message, but the &quot;isinstance&quot; thing confuses me very hard, I never used it before. But this is an important feature, that I would love to integrate.</p>