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

        /* Begin Definitions */

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

        /* End Definitions */

        typeName: 'type',

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

            /**
             * @property {Ext.util.HashMap} all
             * Contains all of the items currently managed
             */
            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 {Object} The item, undefined if not found.
         */
        get : function(id) {
            return this.all.get(id);
        },

        /**
         * Registers an item to be managed
         * @param {Object} item The item to register
         */
        register: function(item) {
            //<debug>
            var all = this.all,
                key = all.getKey(item);

            if (all.containsKey(key)) {
                Ext.Error.raise('Registering duplicate id "' + key + '" with this manager');
            }
            //</debug>
            this.all.add(item);
        },

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

        /**
         * 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 {Function} 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 {Object} 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 (this 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.
         * @param {Function} fn The function to execute.
         * @param {String} fn.key The key of the item
         * @param {Number} fn.value The value of the item
         * @param {Number} fn.length The total number of items in the collection
         * @param {Boolean} fn.return False to cease iteration.
         * @param {Object} scope The scope to execute in. Defaults to `this`.
         */
        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();
        }
    });