// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 22-1: Inheritance
  
  class Square extends Shape {
    // Variables are inherited from the parent.
    // We could also add variables unique to the Square class if we so desire
  
    Square(float x_, float y_, float r_) {
      // If the parent constructor takes arguments then super() needs to pass in those arguments.
      super(x_,y_,r_); 
    }
  
    // Inherits jiggle() from parent
  
    // The square overrides its parent for display.
    void display() {
      rectMode(CENTER);
      fill(175);
      stroke(0);
      rect(x,y,r,r);
    }
  }