old_contents: /* ***** BEGIN LICENSE BLOCK *****
   * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   *
   * The contents of this file are subject to the Mozilla Public License Version
   * 1.1 (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   * http://www.mozilla.org/MPL/
   *
   * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   *
   * The Original Code is Ajax.org Code Editor (ACE).
   *
   * The Initial Developer of the Original Code is
   * Ajax.org B.V.
   * Portions created by the Initial Developer are Copyright (C) 2010
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *      Fabian Jakobs <fabian AT ajax DOT org>
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   *
   * ***** END LICENSE BLOCK ***** */
  
  define(function(require, exports, module) {
  
  var UndoManager = function() {
      this.$undoStack = [];
      this.$redoStack = [];
  };
  
  (function() {
  
      /*this.$doc = null;
      this.setDocument = function(doc) {
          this.$doc = doc;
      };*/
  
      this.execute = function(options) {
          var deltas = options.args[0];
          this.$doc  = options.args[1];
          this.$undoStack.push(deltas);
      };
  
      this.undo = function() {
          var deltas = this.$undoStack.pop();
          if (deltas) {
              this.$doc.undoChanges(deltas);
              this.$redoStack.push(deltas);
          }
      };
  
      this.redo = function() {
          var deltas = this.$redoStack.pop();
          if (deltas) {
              this.$doc.redoChanges(deltas);
              this.$undoStack.push(deltas);
          }
      };
  
  }).call(UndoManager.prototype);
  
  exports.UndoManager = UndoManager;
  });
  
new_contents: /* ***** BEGIN LICENSE BLOCK *****
   * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   *
   * The contents of this file are subject to the Mozilla Public License Version
   * 1.1 (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   * http://www.mozilla.org/MPL/
   *
   * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   *
   * The Original Code is Ajax.org Code Editor (ACE).
   *
   * The Initial Developer of the Original Code is
   * Ajax.org B.V.
   * Portions created by the Initial Developer are Copyright (C) 2010
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *      Fabian Jakobs <fabian AT ajax DOT org>
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   *
   * ***** END LICENSE BLOCK ***** */
  
  define(function(require, exports, module) {
  
  var UndoManager = function() {
      this.$undoStack = [];
      this.$redoStack = [];
  };
  
  (function() {
  
      this.execute = function(options) {
          var deltas = options.args[0];
          this.$doc  = options.args[1];
          this.$undoStack.push(deltas);
      };
  
      this.undo = function() {
          var deltas = this.$undoStack.pop();
          if (deltas) {
              this.$doc.undoChanges(deltas);
              this.$redoStack.push(deltas);
          }
      };
  
      this.redo = function() {
          var deltas = this.$redoStack.pop();
          if (deltas) {
              this.$doc.redoChanges(deltas);
              this.$undoStack.push(deltas);
          }
      };
  
  }).call(UndoManager.prototype);
  
  exports.UndoManager = UndoManager;
  });
  
subject: remove dead code