code: def _connected(self, link_uri):
          
          print('Connected to %s' % link_uri)
  
          # The definition of the logconfig can be made before connecting
          self._lg_stab = LogConfig(name='Stabilizer', period_in_ms=10)
          self._lg_stab.add_variable('stabilizer.roll', 'float')
          self._lg_stab.add_variable('stabilizer.pitch', 'float')
          self._lg_stab.add_variable('stabilizer.yaw', 'float')
  
          # Adding the configuration cannot be done until a Crazyflie is
          # connected, since we need to check that the variables we
          # would like to log are in the TOC.
          try:
              self._cf.log.add_config(self._lg_stab)
              # This callback will receive the data
              self._lg_stab.data_received_cb.add_callback(self._stab_log_data)
              # This callback will be called on errors
              self._lg_stab.error_cb.add_callback(self._stab_log_error)
              # Start the logging
              self._lg_stab.start()
          except KeyError as e:
              print('Could not start log configuration,'
                    '{} not found in TOC'.format(str(e)))
          except AttributeError:
              print('Could not add Stabilizer log config, bad configuration.')
  
          # Start a timer to disconnect in 10s
          t = Timer(5, self._cf.close_link)
          t.start()
docs: This callback is called form the Crazyflie API when a Crazyflie
          has been connected and the TOCs have been downloaded.