import java.awt.geom.Point2D; public interface Vehicle { /** Speed of the vehicle in km/h */ public double speed(); /** Direction of the vehicle in radian, relative to the x-axis */ public double direction(); /** Position of the vehicle */ public Point2D position(); /** * Run the vehicle during a time given in hours. This method modify the position * of the vehicle, following its speed and its direction. */ public void go(double time); }