docs: public HashMap<Integer,ArrayList<TrajectoryEnvelope>> createEnvelopes(int firstRobotID, long durationFirstParking, long durationLastParking, Coordinate[] footprint, Trajectory ... trajectories) {
  
  		HashMap<Integer,ArrayList<TrajectoryEnvelope>> ret = new HashMap<Integer, ArrayList<TrajectoryEnvelope>>();
  		
  		for (int i = 0; i < trajectories.length; i++) {
  			ArrayList<TrajectoryEnvelope> oneRobot = makeEnvelope(i+firstRobotID, durationFirstParking, durationLastParking, trajectories[i], footprint);
  			ret.put(i+firstRobotID, oneRobot);
  		}		
  		return ret;
  	}