The source code

    /**
     * @class Ext.state.Manager
     * This is the global state manager. By default all components that are "state aware" check this class
     * for state information if you don't pass them a custom state provider. In order for this class
     * to be useful, it must be initialized with a provider when your application initializes. Example usage:
     <pre><code>
    // in your initialization function
    init : function(){
       Ext.state.Manager.setProvider(new Ext.state.CookieProvider());
       var win = new Window(...);
       win.restoreState();
    }
     </code></pre>
     * @singleton
     */
    Ext.state.Manager = function(){
        var provider = new Ext.state.Provider();

        return {
            /**
             * Configures the default state provider for your application
             * @param {Provider} stateProvider The state provider to set
             */
            setProvider : function(stateProvider){
                provider = stateProvider;
            },

            /**
             * Returns the current value for a key
             * @param {String} name The key name
             * @param {Mixed} defaultValue The default value to return if the key lookup does not match
             * @return {Mixed} The state data
             */
            get : function(key, defaultValue){
                return provider.get(key, defaultValue);
            },

            /**
             * Sets the value for a key
             * @param {String} name The key name
             * @param {Mixed} value The state data
             */
             set : function(key, value){
                provider.set(key, value);
            },

            /**
             * Clears a value from the state
             * @param {String} name The key name
             */
            clear : function(key){
                provider.clear(key);
            },

            /**
             * Gets the currently configured state provider
             * @return {Provider} The state provider
             */
            getProvider : function(){
                return provider;
            }
        };
    }();