function createLine(points, attrs, radius) {

  if (isNumber(attrs)) {
    radius = attrs;
    attrs = null;
  }

  if (!attrs) {
    attrs = {};
  }

  const line = svgCreate('path', attrs);

  if (isNumber(radius)) {
    line.dataset.cornerRadius = String(radius);
  }

  return updateLine(line, points);
}
@param {Point[]} points
@param {number|Object} [attrs]
@param {number} [radius]

@return {SVGElement}