function _getSegmentMethod(line) {
  const opts = line.options;
  const borderDash = opts.borderDash && opts.borderDash.length;
  const useFastPath = !line._decimated && !line._loop && !opts.tension && opts.cubicInterpolationMode !== 'monotone' && !opts.stepped && !borderDash;
  return useFastPath ? fastPathSegment : pathSegment;
}
@param {LineElement} line - the line
@returns {function}
@private