def METHOD_NAME(data_fixture):
    user = data_fixture.create_user()
    workspace = data_fixture.create_workspace(user=user)
    data_fixture.create_workspace_notification(recipients=[user], workspace=workspace)
    data_fixture.create_user_notification(recipients=[user])
    assert Notification.objects.count() == 2
    NotificationHandler.clear_all_notifications(user, workspace=workspace)
    assert Notification.objects.count() == 0