code: public void drawRect(int x, int y, int w, int h, Color c) {
          int color = c.getRGB();
          for (int i = x; i < x + w; i++) {
              setIntColor(i, y, color);
              setIntColor(i, y + (h - 1), color);
          }
  
          for (int i = y; i < y + h; i++) {
              setIntColor(x, i, color);
              setIntColor(x + (w - 1), i, color);
          }
      }
docs: Draws a rectangle in the image. It�s useful for debugging purposes.
  
  @param x rect�s start position in x-axis
  @param y rect�s start positioj in y-axis
  @param w rect�s width
  @param h rect�s height
  @param c rect�s color