How to use the proton-engine.Position function in proton-engine

createProton(canvas, width, height) {
    this.proton = new Proton();

    const emitter = new Proton.Emitter();
    emitter.damping = 0.008;
    emitter.rate = new Proton.Rate(this.props.num ? this.props.num : 150);

    // Initialize
    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(8));
    emitter.addInitialize(
      new Proton.V(new Proton.Span(0.1, 0.5), new Proton.Span(0, 360), "polar")
    );
    emitter.addInitialize(
      new Proton.Position(
        new Proton.CircleZone(canvas.width / 2, canvas.height / 2, 100)
      )
    );

    // Behaviour
    const crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(0, 0, canvas.width, canvas.height),
      "cross"
    );
    emitter.addBehaviour(crossZoneBehaviour);
    this.repulsion = new Proton.Repulsion(
      {
        x: canvas.width / 2,
        y: canvas.height / 2 - 100
      },
      3,

} else {
                emitter = new Proton.Emitter();
            }
            emitter.rate = new Proton.Rate(num, rps);

            emitter.addInitialize(new Proton.Mass(mass));
            emitter.addInitialize(new Proton.Radius(radius));
            emitter.addInitialize(new Proton.Life(life));
            emitter.addInitialize(new Proton.Velocity(v, tha, "polar"));
            if (body) emitter.addInitialize(new Proton.Body(body));

            var pos = void 0;
            if (position === "all" || position === "screen") {
                pos = new Proton.Position(new Proton.RectZone(0, 0, canvas.width, canvas.height));
            } else if ((typeof position === "undefined" ? "undefined" : _typeof(position)) === "object") {
                pos = new Proton.Position(new Proton.RectZone(position.x, position.y, position.width, position.height));
            } else {
                emitter.p.x = canvas.width / 2;
                emitter.p.y = canvas.height / 2;
            }

            emitter.addInitialize(pos);

            /// behaviour
            var alphaB = alpha ? new Proton.Alpha(alpha[0], alpha[1]) : new Proton.Alpha(0, 1);
            var scaleB = scale ? new Proton.Scale(scale[0], scale[1]) : new Proton.Scale(1, 0.2);
            var colorB = color ? new Proton.Color(color[0], color[1]) : new Proton.Color(this.colors);

            emitter.addBehaviour(alphaB);
            emitter.addBehaviour(scaleB);
            if (!body) emitter.addBehaviour(colorB);

this.props.num ? new Proton.Span(this.props.num) : new Proton.Span(4, 8),
      new Proton.Span(0.1, 0.25)
    );

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(20, 200));
    emitter.addInitialize(new Proton.Life(2, 4));
    emitter.addInitialize(
      new Proton.Velocity(
        new Proton.Span(4, 7),
        new Proton.Span(0, 360),
        "polar"
      )
    );
    emitter.addInitialize(
      new Proton.Position(new Proton.CircleZone(width / 2, height / 2, 100))
    );

    emitter.addBehaviour(new Proton.Alpha(1, 0));
    emitter.addBehaviour(new Proton.Scale(0.2, 1));
    emitter.addBehaviour(this.createCustomBehaviour());
    emitter.addBehaviour(new Proton.Color(this.colors, "random"));
    emitter.emit();
    this.proton.addEmitter(emitter);

    const renderer = new Proton.CanvasRenderer(canvas);
    this.proton.addRenderer(renderer);
  }

createProton(canvas, width, height) {
    this.proton = new Proton();
    const emitter = new Proton.Emitter();
    emitter.rate = new Proton.Rate(
      this.props.num ? new Proton.Span(this.props.num) : new Proton.Span(5, 8),
      new Proton.Span(0.1, 0.25)
    );

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(20, 200));
    emitter.addInitialize(new Proton.Life(2, 4));
    emitter.addInitialize(
      new Proton.Position(new Proton.RectZone(0, 0, width, height))
    );

    emitter.addBehaviour(new Proton.Alpha(0, 1, Infinity, Proton.easeOutCubic));
    emitter.addBehaviour(new Proton.Scale(1, 0, Infinity, Proton.easeOutCubic));
    emitter.addBehaviour(new Proton.Color(this.colors, "random"));

    emitter.emit();
    this.proton.addEmitter(emitter);

    const renderer = new Proton.CanvasRenderer(canvas);
    this.proton.addRenderer(renderer);
  }

createProton(canvas, width, height) {
    this.proton = new Proton();

    const emitter = new Proton.Emitter();
    emitter.rate = new Proton.Rate(
      this.props.num ? new Proton.Span(this.props.num) : new Proton.Span(100),
      new Proton.Span(0.05, 0.2)
    );

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(1, 4));
    emitter.addInitialize(new Proton.Life(Infinity));

    const pointZone = new Proton.Position(
      new Proton.RectZone(0, 0, width, height)
    );
    emitter.addInitialize(pointZone);
    emitter.addInitialize(
      new Proton.Velocity(
        new Proton.Span(0.3, 0.6),
        new Proton.Span(0, 360),
        "polar"
      )
    );

    emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.2, 0.9)));
    emitter.addBehaviour(new Proton.Color(this.props.color || "#333"));
    this.crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(0, 0, width, height),
      "cross"

createProton(canvas, width, height) {
    this.proton = new Proton();

    const emitter = new Proton.Emitter();
    emitter.rate = new Proton.Rate(
      new Proton.Span(100),
      new Proton.Span(0.05, 0.2)
    );

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(1, 4));
    emitter.addInitialize(new Proton.Life(Infinity));

    const pointZone = new Proton.Position(
      new Proton.RectZone(0, 0, width, height)
    );
    emitter.addInitialize(pointZone);
    emitter.addInitialize(
      new Proton.Velocity(
        new Proton.Span(0.3, 0.6),
        new Proton.Span(0, 360),
        "polar"
      )
    );

    emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.2, 0.9)));
    emitter.addBehaviour(new Proton.Color("#ffffff"));
    this.crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(0, 0, width, height),
      "cross"

createProton(canvas, width, height) {
    this.proton = new Proton();
    const emitter = new Proton.Emitter();
    emitter.rate = new Proton.Rate(this.props.num ? this.props.num : 50);
    emitter.damping = 0;

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(4, 70));
    emitter.addInitialize(
      new Proton.Velocity(new Proton.Span(2, 10), new Proton.Span(0), "polar")
    );
    emitter.addInitialize(
      new Proton.Position(
        new Proton.LineZone(0, canvas.height, canvas.width, canvas.height)
      )
    );

    const dis = 150;
    const crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(
        0 - dis,
        0 - dis,
        canvas.width + 2 * dis,
        canvas.height + 2 * dis
      ),
      "cross"
    );
    emitter.addBehaviour(crossZoneBehaviour);
    emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.1, 0.55)));