@param {IncomingMessage} req
@param {string} [req.url]

@param {ServerResponse} res
@param {Function} res.send
@param {Function} res.setHeader

@param {Function} next

@returns {*}
function faviconRequestHandler( req, res, next ) {
  var icon = ''

  if ( typeof req.url !== 'string' ) {
    return next()
  }

  if ( url.parse( req.url ).pathname !== '/favicon.ico' ) {
    return next()
  }

  res.setHeader( 'content-length', icon.length )
  res.setHeader( 'content-type', 'image/x-icon' )
  res.send( icon )
}