docs: def init_app(self, app):
          """Inititialise the extension with the app object.
  
          :param app: Your application object
          """
          host = app.config.get('STATS_HOSTNAME', 'localhost')
          port = app.config.get('STATS_PORT', 8125)
          base_key = app.config.get('STATS_BASE_KEY', app.name)
  
          client = _StatsClient(
              host=host,
              port=port,
              prefix=base_key,
          )
  
          app.before_request(client.flask_time_start)
          app.after_request(client.flask_time_end)
  
          if not hasattr(app, 'extensions'):
              app.extensions = {}
          app.extensions.setdefault('stats', {})
          app.extensions['stats'][self] = client
  
          return client