code: async def on_raw_chghost(self, message):
          
          if 'chghost' not in self._capabilities or not self._capabilities['chghost']:
              return
  
          nick, _ = self._parse_user(message.source)
          if nick not in self.users:
              return
  
          # Update user and host.
          metadata = {
              'username': message.params[0],
              'hostname': message.params[1]
          }
          self._sync_user(nick, metadata)
docs: Change user and/or host of user.