slot_1:
  id: 1
  start_at: 2012-04-11 06:00:00.000000000 Z
  end_at: 2012-04-11 10:00:00.000000000 Z
  reservation_id: 1
  created_at: 2012-03-12 13:40:22.342717000 Z
  updated_at: 2012-03-12 13:40:22.342717000 Z
  availability_id: 12
  ex_start_at:
  canceled_at:
  ex_end_at:
  offered: