/// <summary>
        /// Instantiates and manages the viewstate providers according to the
        /// registered providers in the "viewStateServices" section in web.config.
        /// </summary>
        private static void LoadProviders()
        {
            // providers are loaded just once
            if (_provider == null)
            {
                // Synchronize the process of loading the providers
                lock (_syncLock)
                {
                    // Confirm that _provider is still null
                    if (_provider == null)
                    {
                        // Get a reference to the <viewstateService> section
                        ViewStateProviderServiceSection section = (ViewStateProviderServiceSection)
                                                                  WebConfigurationManager.GetSection("system.web/viewstateService");

                        // Load all registered providers
                        _providers = new ViewStateProviderCollection();

                        ProvidersHelper.InstantiateProviders
                            (section.Providers, _providers,
                            typeof(ViewStateProviderBase));

                        // Set _provider to the default provider
                        _provider = _providers[section.DefaultProvider];
                    }
                }
            }
        }
        /// <summary>
        /// Instantiates and manages the viewstate providers according to the 
        /// registered providers in the "viewStateServices" section in web.config.
        /// </summary>
        private static void LoadProviders()
        {
            // providers are loaded just once
            if (_provider == null)
            {
                // Synchronize the process of loading the providers
                lock (_syncLock)
                {
                    // Confirm that _provider is still null
                    if (_provider == null)
                    {
                        // Get a reference to the <viewstateService> section
                        ViewStateProviderServiceSection section = (ViewStateProviderServiceSection)
                            WebConfigurationManager.GetSection("system.web/viewstateService");

                        // Load all registered providers
                        _providers = new ViewStateProviderCollection();

                        ProvidersHelper.InstantiateProviders
                            (section.Providers, _providers,
                            typeof(ViewStateProviderBase));

                        // Set _provider to the default provider
                        _provider = _providers[section.DefaultProvider];
                    }
                }
            }
        }