old_contents: // leave at least 2 line with only a star on it below, or doc generation fails
  /**
   *
   *
   * Placeholder for custom user javascript
   * mainly to be overridden in profile/static/custom/custom.js
   * This will always be an empty file in IPython
   *
   * User could add any javascript in the `profile/static/custom/custom.js` file
   * (and should create it if it does not exist).
   * It will be executed by the ipython notebook at load time.
   *
   * Same thing with `profile/static/custom/custom.css` to inject custom css into the notebook.
   *
   * __Example 1:__
   *
   * Create a custom button in toolbar that execute `%qtconsole` in kernel
   * and hence open a qtconsole attached to the same kernel as the current notebook
   *
   *    IPython.events.on('app_initialized.NotebookApp', function(){
   *        IPython.toolbar.add_buttons_group([
   *            {
   *                 'label'   : 'run qtconsole',
   *                 'icon'    : 'icon-terminal', // select your icon from http://fortawesome.github.io/Font-Awesome/icons
   *                 'callback': function () {
   *                     IPython.notebook.kernel.execute('%qtconsole')
   *                 }
   *            }
   *            // add more button here if needed.
   *            ]);
   *    });
   *
   * __Example 2:__
   *
   * At the completion of the dashboard loading, load an unofficial javascript extension
   * that is installed in profile/static/custom/ 
   *
   *    IPython.events.on('app_initialized.DashboardApp', function(){
   *        require(['custom/unofficial_extension.js'])
   *    });
   *
   * __Example 3:__
   *
   *  Use `jQuery.getScript(url [, success(script, textStatus, jqXHR)] );`
   *  to load custom script into the notebook.
   *
   *    // to load the metadata ui extension example.
   *    $.getScript('/static/notebook/js/celltoolbarpresets/example.js');
   *    // or
   *    // to load the metadata ui extension to control slideshow mode / reveal js for nbconvert
   *    $.getScript('/static/notebook/js/celltoolbarpresets/slideshow.js');
   *
   *
   * @module IPython
   * @namespace IPython
   * @class customjs
   * @static
   */
  
new_contents: // leave at least 2 line with only a star on it below, or doc generation fails
  /**
   *
   *
   * Placeholder for custom user javascript
   * mainly to be overridden in profile/static/custom/custom.js
   * This will always be an empty file in IPython
   *
   * User could add any javascript in the `profile/static/custom/custom.js` file
   * (and should create it if it does not exist).
   * It will be executed by the ipython notebook at load time.
   *
   * Same thing with `profile/static/custom/custom.css` to inject custom css into the notebook.
   * 
   * Classes and functions are available at load time and may be accessed plainly: 
   * 
   *     IPython.Cell.options_default.cm_config.extraKeys = {Home: "goLineLeft", End: "goLineRight"};
   * 
   * Instances are created later however and must be accessed using events:
   * 
   *     $([IPython.events]).on("app_initialized.NotebookApp", function () {
   *         IPython.keyboard_manager....
   *     });
   *
   * __Example 1:__
   *
   * Create a custom button in toolbar that execute `%qtconsole` in kernel
   * and hence open a qtconsole attached to the same kernel as the current notebook
   *
   *    IPython.events.on('app_initialized.NotebookApp', function(){
   *        IPython.toolbar.add_buttons_group([
   *            {
   *                 'label'   : 'run qtconsole',
   *                 'icon'    : 'icon-terminal', // select your icon from http://fortawesome.github.io/Font-Awesome/icons
   *                 'callback': function () {
   *                     IPython.notebook.kernel.execute('%qtconsole')
   *                 }
   *            }
   *            // add more button here if needed.
   *            ]);
   *    });
   *
   * __Example 2:__
   *
   * At the completion of the dashboard loading, load an unofficial javascript extension
   * that is installed in profile/static/custom/ 
   *
   *    IPython.events.on('app_initialized.DashboardApp', function(){
   *        require(['custom/unofficial_extension.js'])
   *    });
   *
   * __Example 3:__
   *
   *  Use `jQuery.getScript(url [, success(script, textStatus, jqXHR)] );`
   *  to load custom script into the notebook.
   *
   *    // to load the metadata ui extension example.
   *    $.getScript('/static/notebook/js/celltoolbarpresets/example.js');
   *    // or
   *    // to load the metadata ui extension to control slideshow mode / reveal js for nbconvert
   *    $.getScript('/static/notebook/js/celltoolbarpresets/slideshow.js');
   *
   *
   * @module IPython
   * @namespace IPython
   * @class customjs
   * @static
   */
  
subject: Update custom.js