How to use the vis-util.HSVToRGB function in vis-util

let radius = 0.98 * Math.min(Math.sqrt(x * x + y * y), centerX);

    let newTop = Math.cos(angle) * radius + centerY;
    let newLeft = Math.sin(angle) * radius + centerX;

    this.colorPickerSelector.style.top = newTop - 0.5 * this.colorPickerSelector.clientHeight + 'px';
    this.colorPickerSelector.style.left = newLeft - 0.5 * this.colorPickerSelector.clientWidth + 'px';

    // set color
    let h = angle / (2 * Math.PI);
    h = h < 0 ? h + 1 : h;
    let s = radius / this.r;
    let hsv = util.RGBToHSV(this.color.r, this.color.g, this.color.b);
    hsv.h = h;
    hsv.s = s;
    let rgba = util.HSVToRGB(hsv.h, hsv.s, hsv.v);
    rgba['a'] = this.color.a;
    this.color = rgba;

    // update previews
    this.initialColorDiv.style.backgroundColor = 'rgba(' + this.initialColor.r + ',' + this.initialColor.g + ',' + this.initialColor.b + ',' + this.initialColor.a + ')';
    this.newColorDiv.style.backgroundColor = 'rgba(' + this.color.r + ',' + this.color.g + ',' + this.color.b + ',' + this.color.a + ')';
  }
}

ctx.clearRect(0, 0, w, h);


      // draw hue circle
      let x, y, hue, sat;
      this.centerCoordinates = {x: w * 0.5, y: h * 0.5};
      this.r = 0.49 * w;
      let angleConvert = (2 * Math.PI) / 360;
      let hfac = 1 / 360;
      let sfac = 1 / this.r;
      let rgb;
      for (hue = 0; hue < 360; hue++) {
        for (sat = 0; sat < this.r; sat++) {
          x = this.centerCoordinates.x + sat * Math.sin(angleConvert * hue);
          y = this.centerCoordinates.y + sat * Math.cos(angleConvert * hue);
          rgb = util.HSVToRGB(hue * hfac, sat * sfac, 1);
          ctx.fillStyle = 'rgb(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ')';
          ctx.fillRect(x - 0.5, y - 0.5, 2, 2);
        }
      }
      ctx.strokeStyle = 'rgba(0,0,0,1)';
      ctx.circle(this.centerCoordinates.x, this.centerCoordinates.y, this.r);
      ctx.stroke();

      this.hueCircle = ctx.getImageData(0,0,w,h);
    }
    this.generated = true;
  }

_setBrightness(value) {
    let hsv = util.RGBToHSV(this.color.r, this.color.g, this.color.b);
    hsv.v = value / 100;
    let rgba = util.HSVToRGB(hsv.h, hsv.s, hsv.v);
    rgba['a'] = this.color.a;
    this.color = rgba;
    this._updatePicker();
  }