function normalize(type) {
  switch (type) {
    case 'urlencoded': return 'application/x-www-form-urlencoded';
    case 'multipart':
      type = 'multipart/*';
      break;
  }

  return type[0] === '+' || ~type.indexOf('/')
    ? type
    : mime.lookup(type)
}
Normalize a mime type.
If it's a shorthand, expand it to a valid mime type.

In general, you probably want:

  var type = is(req, ['urlencoded', 'json', 'multipart']);

Then use the appropriate body parsers.
These three are the most common request body types
and are thus ensured to work.

@param {String} type
@api private