How to use the proton-engine.Mass 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);

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

    const emitter = new Proton.Emitter();
    emitter.damping = 0.008;
    emitter.rate = new Proton.Rate(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);

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

    const emitter = new Proton.Emitter();
    emitter.rate = new Proton.Rate(20);
    emitter.damping = 0.008;

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(30, 600));
    emitter.addInitialize(
      new Proton.Velocity(
        new Proton.Span(0.5),
        new Proton.Span(0, 360),
        "polar"
      )
    );
    emitter.addInitialize(
      new Proton.Position(
        new Proton.RectZone(0, 0, canvas.width, canvas.height)
      )
    );

    const crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(0, 0, canvas.width, canvas.height),

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

    const emitter = new Proton.Emitter();
    emitter.rate = new Proton.Rate(this.props.num || 20);
    emitter.damping = 0.008;

    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(30, 600));
    emitter.addInitialize(
      new Proton.Velocity(
        new Proton.Span(0.5),
        new Proton.Span(0, 360),
        "polar"
      )
    );
    emitter.addInitialize(
      new Proton.Position(
        new Proton.RectZone(0, 0, canvas.width, canvas.height)
      )
    );

    const crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(0, 0, canvas.width, canvas.height),

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)));

value: function createMiniEmitter(canvas) {
      var miniEmitter = new Proton.Emitter();
      miniEmitter.rate = new Proton.Rate(new Proton.Span(3, 6), new Proton.Span(1, 2));

      miniEmitter.addInitialize(new Proton.Mass(1));
      miniEmitter.radiusInitialize = new Proton.Radius();
      miniEmitter.addInitialize(miniEmitter.radiusInitialize);
      miniEmitter.addInitialize(new Proton.Life(0.5, 1));
      miniEmitter.addInitialize(new Proton.V(new Proton.Span(1.5, 3), new Proton.Span(0, 70, true), "polar"));

      miniEmitter.colorBehaviour = new Proton.Color("#ffffff");
      miniEmitter.addBehaviour(new Proton.Alpha(1, 0));
      miniEmitter.addBehaviour(miniEmitter.colorBehaviour);
      miniEmitter.addBehaviour(new Proton.Gravity(4));
      miniEmitter.addBehaviour(new Proton.Collision(miniEmitter));
      miniEmitter.addBehaviour(new Proton.CrossZone(new Proton.RectZone(0, 0, canvas.width, canvas.height), "bound"));
      this.proton.addEmitter(miniEmitter);

      this.miniEmitter = miniEmitter;
    }
  }, {

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

    const emitter = new Proton.Emitter();
    emitter.damping = 0.008;
    emitter.rate = new Proton.Rate(250);
    emitter.addInitialize(new Proton.Mass(1));
    emitter.addInitialize(new Proton.Radius(4));
    emitter.addInitialize(
      new Proton.Velocity(
        new Proton.Span(1.5),
        new Proton.Span(0, 360),
        "polar"
      )
    );
    const mouseObj = {
      x: width / 2,
      y: height / 2
    };

    const attractionBehaviour = new Proton.Attraction(mouseObj, 0, 0);
    const crossZoneBehaviour = new Proton.CrossZone(
      new Proton.RectZone(0, 0, canvas.width, canvas.height),

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)));