_createFilter(sourceImg, type, options) {
    let filterObj;
    // capitalize first letter for matching with fabric image filter name
    const fabricType = this._getFabricFilterType(type);
    const ImageFilter = fabric.Image.filters[fabricType];
    if (ImageFilter) {
      filterObj = new ImageFilter(options);
      filterObj.options = options;
      sourceImg.filters.push(filterObj);
    }

    return filterObj;
  }
Create filter instance
@param {fabric.Image} sourceImg - Source image to apply filter
@param {string} type - Filter type
@param {Object} [options] - Options of filter
@returns {Object} Fabric object of filter
@private