new_contents: from unittest.mock import Mock
  
  from jacquard.cli import main
  from jacquard.storage.dummy import DummyStore
  
  
  def test_launch():
      config = Mock()
      config.storage = DummyStore('', data={
          'experiments/foo': {
              'branches': [
                  {
                      'id': 'bar',
                      'settings': {},
                  },
              ],
          },
      })
  
      main(('launch', 'foo'), config=config)
  
      assert 'launched' in config.storage['experiments/foo']
      assert 'foo' in config.storage['active-experiments']
  
subject: Add experiment launch test