lib/utils.js
function quality(str) {
  var parts = str.split(/ *; */),
      val = parts[0];

  var q = parts[1] ? parseFloat(parts[1].split(/ *= */)[1]) : 1;

  return { value: val, quality: q };
}
function quality(str) {
  var parts = str.split(/ *; */),
      val = parts[0];

  var q = parts[1] ? parseFloat(parts[1].split(/ *= */)[1]) : 1;

  return { value: val, quality: q };
}
Parse quality `str` returning an
object with `.value` and `.quality`.

@param {String} str
@return {Object}
@api private