Constructor not defined [Processing]
<p>I'm doing a really basic tutorial on ArrayList / Particle systems. I keep getting a "constructor is undefined error" and I can't figure out why. Googling brings up a lot of more complicated question/answers. What am I missing? Did this change in the last year? </p>

<pre><code>ArrayList&lt;Particle&gt; plist;

void setup(){
    size(640, 360);
    plist = new ArrayList&lt;Particle&gt;();
    println(plist);
    plist.add(new Particle());
}

void draw(){
    background(255);


}


class Particle {
  PVector location;
  PVector velocity;
  PVector acceleration;
  float lifespan;

  Particle(PVector l){
    // For demonstration purposes we assign the Particle an initial velocity and constant acceleration.
    acceleration = new PVector(0,0.05);
    velocity = new PVector(random(-1,1),random(-2,0));
    location = l.get();
    lifespan = 255;
  }

  void run(){
    update();
    display();
  }

  void update(){
    velocity.add(acceleration);
    location.add(velocity);
    lifespan -= 2.0;
  }

  void display(){
    stroke(0, lifespan);
    fill(175, lifespan);
    ellipse(location.x, location.y,8,8);
  }

  boolean isDead(){
    if(lifespan &lt; 0.0){
      return true;
    }else{
      return false;
    }
  }
}
</code></pre>