/**
  * Calculates a spin with which the given karttu will be at given angle when it lands.
  *
  * @param k karttu which desired spin should be calculated
  * @param angle angle at which the karttu should land
  * @return spin at which Karttu k will land at angle angle
  */
 public static double calculateDesiredSpin(Karttu k, double angle) {
   int time = calculateLandingTime(k);
   double spin = (((angle - k.getAngle()) % 360 + 360) % 360) / time;
   return spin;
 }
 /**
  * Calculates the angle given karttu will have when it lands.
  *
  * @param k karttu which landing angle to calculate
  * @return angle of landing
  */
 public static double calculateLandingAngle(Karttu k) {
   int time = calculateLandingTime(k);
   double angle = k.getAngle() + k.getSpin() * time;
   angle %= 360;
   return angle;
 }