code: public FlightInfoExtendedBuilder setFlightSchedule(Calendar departureTime,
  			Calendar arrivalTime, Calendar boardingTime) {
  		FlightSchedule flightSchedule = new FlightSchedule(departureTime,
  				arrivalTime, boardingTime);
  		this.flightInfo.setFlightSchedule(flightSchedule);
  		return this;
  	}
docs: Sets the {@link FlightSchedule} object for the current
  {@link FlightInfoExtended} object. This field is mandatory for this
  object and can't be null.
  
  @param departureTime
  the departure time. It can't be null.
  @param arrivalTime
  the arrival time. It can't be null.
  @param boardingTime
  the boarding time. This field is optional.
  @return this builder.