constructor(x, y, shape) {

    this.x = x;

    this.y = y;

    this.px = x;

    this.py = y;

  }

  update() {

    this.px = this.x;

    this.py = this.y;

    this.x += random(-5, 5);

    this.y += random(-5, 5);

  }

  show() {

    ellipseMode(CENTER);

    noStroke();

    fill(random(255), random(255), random(255));

    ellipse(this.x, this.y, 20, 20);

  }

}