code: function CommandDispatcher (tree, definition, commandBumper) {
    if (!tree || !_.isObject(tree) || !_.isFunction(tree.getCommandHandler)) {
      var err = new Error('Please pass a valid tree!');
      debug(err);
      throw err;
    }
  
    if (!definition || !_.isObject(definition)) {
      var err = new Error('Please pass a valid command definition!');
      debug(err);
      throw err;
    }
  
    this.tree = tree;
    this.definition = definition;
  
    this.commandBumper = commandBumper;
  }
docs: CommandDispatcher constructor
  @param {Object} tree          The tree object.
  @param {Object} definition    The definition object.
  @param {Object} commandBunper The commandBumper object. [optional]
  @constructor