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

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),
      "cross"
    );
    emitter.addBehaviour(crossZoneBehaviour);
    emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.35, 0.55)));
    emitter.addBehaviour(new Proton.Color(this.getColor()));
    emitter.addBehaviour(new Proton.RandomDrift(50, 50, 0.5));

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

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

    this.crossZoneBehaviour = crossZoneBehaviour;
  }

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),
      "cross"
    );
    emitter.addBehaviour(crossZoneBehaviour);
    emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.35, 0.55)));
    emitter.addBehaviour(new Proton.Color(this.colors, "random"));
    emitter.addBehaviour(new Proton.RandomDrift(50, 50, 0.5));

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

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

    this.crossZoneBehaviour = crossZoneBehaviour;
  }

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"
    );
    emitter.addBehaviour(this.crossZoneBehaviour);

    emitter.emit("once");
    emitter.damping = 0;
    this.proton.addEmitter(emitter);
    this.proton.addRenderer(this.createRenderer(canvas, emitter));
  }

value: function createProton(canvas, width, height) {
      this.proton = new Proton();
      var 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)));

      var dis = 150;
      var 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)));
      emitter.addBehaviour(new Proton.Color(this.colors));

      emitter.emit("once");
      this.proton.addEmitter(emitter);
      var renderer = this.createRenderer(canvas);
      this.proton.addRenderer(renderer);

      this.crossZoneBehaviour = crossZoneBehaviour;
      emitter.preEmit(2);
    }
  }, {

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

      var 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)));

      var crossZoneBehaviour = new Proton.CrossZone(new Proton.RectZone(0, 0, canvas.width, canvas.height), "cross");
      emitter.addBehaviour(crossZoneBehaviour);
      emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.35, 0.55)));
      emitter.addBehaviour(new Proton.Color(this.getColor()));
      emitter.addBehaviour(new Proton.RandomDrift(50, 50, 0.5));

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

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

      this.crossZoneBehaviour = crossZoneBehaviour;
    }
  }, {

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)));
    emitter.addBehaviour(new Proton.Color(this.colors));

    emitter.emit("once");
    this.proton.addEmitter(emitter);
    const renderer = this.createRenderer(canvas);
    this.proton.addRenderer(renderer);

    this.crossZoneBehaviour = crossZoneBehaviour;
    emitter.preEmit(2);
  }

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"
    );
    emitter.addBehaviour(this.crossZoneBehaviour);

    emitter.emit("once");
    emitter.damping = 0;
    this.proton.addEmitter(emitter);
    this.proton.addRenderer(this.createRenderer(canvas, emitter));
  }

const createEmitter = (node, config = {}) => {
  const emitter = new Proton.Emitter();
  emitter.rate = config.num
    ? new Proton.Rate(Proton.getSpan(Math.floor(config.num * 0.7), config.num), 0.1)
    : new Proton.Rate(Proton.getSpan(6, 8), 0.1);

  const life = config.life ? new Proton.Life(config.life) : new Proton.Life(0.5, 1.2);
  const color = config.color || getDefaultColor(node);
  const tha = config.tha ? new Proton.Span(config.tha[0], config.tha[1]) : new Proton.Span(-30, 30);
  const v = config.v ? new Proton.Span(config.v * 0.8, config.v) : new Proton.Span(0.6, 1.2);

  if (config.alpha) {
    if (Array.isArray(config.alpha)) {
      emitter.addBehaviour(new Proton.Alpha(config.alpha[0], config.alpha[1]));
    } else {
      emitter.addBehaviour(new Proton.Alpha(config.alpha));
    }
  } else {
    emitter.addBehaviour(new Proton.Alpha(Proton.getSpan(0.6, 0.9)));
  }