old_contents: 'use strict';
  
  var createErrorClass = require('create-error-class');
  
  /* eslint-disable no-invalid-this */
  module.exports = createErrorClass('MissingMiddleware', function (name) {
  	this.message = name + '\n';
  	this.message += '\tAdd it before using this middleware: app.use(require(\'' + name + '\')());\n';
  	this.message += '\tOr read documentation at http://npmjs.com/' + name;
  });
  
new_contents: 'use strict';
  
  var createErrorClass = require('create-error-class');
  
  /* eslint-disable no-invalid-this */
  module.exports = createErrorClass('MissingMiddleware', function (name) {
  	if (!name) {
  		throw new Error('name argument is required');
  	}
  
  	this.message = name + '\n';
  	this.message += '\tAdd it before using this middleware: app.use(require(\'' + name + '\')());\n';
  	this.message += '\tOr read documentation at http://npmjs.com/' + name;
  });
  
subject: Add name argument validation