new_contents: from skylines.model import User
  from tests.api import auth_for
  from tests.data import add_fixtures, users
  
  
  def test_generate(db_session, client):
      john = users.john()
      add_fixtures(db_session, john)
  
      old_key = john.tracking_key_hex
  
      res = client.post('/settings/tracking/key', headers=auth_for(john))
      assert res.status_code == 200
  
      new_key = res.json['key']
      assert new_key != old_key
      assert User.get(john.id).tracking_key_hex == new_key
  
  
  def test_unauthenticated(db_session, client):
      res = client.post('/settings/tracking/key')
      assert res.status_code == 401
  
subject: Add "POST /settings/tracking/key" tests