text: // The Nature of Code
  // Daniel Shiffman
  // http://natureofcode.com
  
  // Child class constructor
  function Particle(position, radius, range, strength) {
    VerletParticle2D.call(this,position);
    this.r = radius;
    physics.addParticle(this);
    physics.addBehavior(new AttractionBehavior(this, range, strength));
  
    // Override the display method
    this.display = function(){
      fill(200,0,0);
      stroke(200);
      strokeWeight(0);
      ellipse(this.x,this.y,this.r*2,this.r*2);
    }
  }
  
  // Inherit from the parent class
  Particle.prototype = Object.create(VerletParticle2D.prototype);
  Particle.prototype.constructor = Particle;
  