new_contents: data_types = {
      'ack': 1,
      'data': 2,
      'low_latency_data': 3,
      'data_with_ack': 4
  }
  data_type_names = {v:k for k, v in data_types.items()}
  
  characteristic_ids = {
      'non_ack': 'fa0a',
      'ack': 'fa0b',
      'emergency': 'fa0c',
      'battery': 'fb0f'
  }
  
  
  # list is not complete
  projects = {
      'common': {
          'project_id': 0,
          'classes': {
              'CommonState': {
                  'class_id': 5,
                  'commands': (
                      "AllStatesChanged", "BatteryStateChanged",
                      "MassStorageStateListChanged", "MassStorageInfoStateListChanged",
                      "CurrentDateChanged", "CurrentTimeChanged",
                      "MassStorageInfoRemainingListChanged", "WifiSignalChanged",
                      "SensorsStatesListChanged", "ProductModel",
                      "CountryListKnown"
                  )
              }
          },
      },
      'mini_drone': {
          'project_id': 2,
          'classes': {
              'Piloting': {
                  'class_id': 0,
                  'commands': (
                      'FlatTrim', 'TakeOff',
                      'PCMD', 'Landing',
                      'Emergency', 'AutoTakeOffMode')
              },
              "SpeedSettings": {
                  'class_id': 1,
                  'commands': (
                      'MaxVerticalSpeed', 'MaxRotationSpeed',
                      'Wheels', 'MaxHorizontalSpeed',
                  )
              },
          }
      },
  }
  
  project_names = {v['project_id']:k for k,v in projects.items()}
  command_classes_names = {(v['project_id'], vv['class_id']):kk
                           for k,v in projects.items()
                           for kk,vv in v['classes'].items()}
  command_names = {(v['project_id'], vv['class_id'], vv['commands'].index(cmd)):cmd
                   for k,v in projects.items()
                   for kk,vv in v['classes'].items()
                   for cmd in vv['commands']}
  
  UPDATE_NOTIFICATION_DESCRIPTOR_UUID = "00002902-0000-1000-8000-00805f9b34fb"
  
subject: add ARSDK constants