constructor () {
    super(BookingHandler, BookingModel, {
      create: obj => typeof obj === 'string' ? null : ({type: 'CREATE_BOOKING', payload: obj.reduxModel()}),
      update: obj => typeof obj === 'string' ? null : ({type: 'UPDATE_BOOKING', payload: obj.reduxModel()}),
      delete: obj => typeof obj !== 'string' ? null : ({type: 'DELETE_BOOKING', payload: obj})