    /**
     * @class Ext.AbstractManager
     * @extends Object
     * Base Manager class
     */
    Ext.define('Ext.AbstractManager', {

        /* Begin Definitions */

        requires: ['Ext.util.HashMap'],

        /* End Definitions */

        typeName: 'type',

        constructor: function(config) {
            Ext.apply(this, config || {});

            /**
             * Contains all of the items currently managed
             * @property all
             * @type Ext.util.MixedCollection
             */
            this.all = Ext.create('Ext.util.HashMap');

            this.types = {};
        },

        /**
         * Returns an item by id.
         * For additional details see {@link Ext.util.HashMap#get}.
         * @param {String} id The id of the item
         * @return {Mixed} The item, <code>undefined</code> if not found.
         */
        get : function(id) {
            return this.all.get(id);
        },

        /**
         * Registers an item to be managed
         * @param {Mixed} item The item to register
         */
        register: function(item) {
            this.all.add(item);
        },

        /**
         * Unregisters an item by removing it from this manager
         * @param {Mixed} item The item to unregister
         */
        unregister: function(item) {
            this.all.remove(item);
        },

        /**
         * <p>Registers a new item constructor, keyed by a type key.
         * @param {String} type The mnemonic string by which the class may be looked up.
         * @param {Constructor} cls The new instance class.
         */
        registerType : function(type, cls) {
            this.types[type] = cls;
            cls[this.typeName] = type;
        },

        /**
         * Checks if an item type is registered.
         * @param {String} type The mnemonic string by which the class may be looked up
         * @return {Boolean} Whether the type is registered.
         */
        isRegistered : function(type){
            return this.types[type] !== undefined;
        },

        /**
         * Creates and returns an instance of whatever this manager manages, based on the supplied type and config object
         * @param {Object} config The config object
         * @param {String} defaultType If no type is discovered in the config object, we fall back to this type
         * @return {Mixed} The instance of whatever this manager is managing
         */
        create: function(config, defaultType) {
            var type        = config[this.typeName] || config.type || defaultType,
                Constructor = this.types[type];

            //<debug>
            if (Constructor == undefined) {
                Ext.Error.raise("The '" + type + "' type has not been registered with this manager");
            }
            //</debug>

            return new Constructor(config);
        },

        /**
         * Registers a function that will be called when an item with the specified id is added to the manager. This will happen on instantiation.
         * @param {String} id The item id
         * @param {Function} fn The callback function. Called with a single parameter, the item.
         * @param {Object} scope The scope (<code>this</code> reference) in which the callback is executed. Defaults to the item.
         */
        onAvailable : function(id, fn, scope){
            var all = this.all,
                item;

            if (all.containsKey(id)) {
                item = all.get(id);
                fn.call(scope || item, item);
            } else {
                all.on('add', function(map, key, item){
                    if (key == id) {
                        fn.call(scope || item, item);
                        all.un('add', fn, scope);
                    }
                });
            }
        },

        /**
         * Executes the specified function once for each item in the collection.
         * Returning false from the function will cease iteration.
         *
         * The paramaters passed to the function are:
         * <div class="mdetail-params"><ul>
         * <li><b>key</b> : String<p class="sub-desc">The key of the item</p></li>
         * <li><b>value</b> : Number<p class="sub-desc">The value of the item</p></li>
         * <li><b>length</b> : Number<p class="sub-desc">The total number of items in the collection</p></li>
         * </ul></div>
         * @param {Object} fn The function to execute.
         * @param {Object} scope The scope to execute in. Defaults to <tt>this</tt>.
         */
        each: function(fn, scope){
            this.all.each(fn, scope || this);
        },

        /**
         * Gets the number of items in the collection.
         * @return {Number} The number of items in the collection.
         */
        getCount: function(){
            return this.all.getCount();
        }
    });