code: public static double Chebyshev(double x1, double y1, double x2, double y2) {
          double max = Math.max(Math.abs(x1 - x2), Math.abs(y1 - y2));
          return max;
      }
docs: Gets the Chebyshev distance between two points.
  
  @param x1 X1 axis coordinate.
  @param y1 Y1 axis coordinate.
  @param x2 X2 axis coordinate.
  @param y2 Y2 axis coordinate.
  @return The Chebyshev distance between x and y.