text: 'use strict';
  
  /**
   * Modifier to add a twitter URl if a twitter username
   * exists on the context.
   */
  
  module.exports = function twitter_(verb) {
    var username = verb.get('data.twitter.username');
    if (username) {
      verb.set('data.twitter.url', 'http://twitter/' + username);
    }
  };
  