public void OnCreateGUI()
        {
            var newTab = m_PackageManagerPrefs.lastUsedPackageFilter ?? PackageFiltering.k_DefaultFilterTab;

            // set the current filter tab value after all the callback system has been setup so that we don't miss any callbacks
            m_PackageFiltering.currentFilterTab = newTab;

            if (m_PageManager.GetRefreshTimestamp(newTab) == 0)
            {
                DelayRefresh(newTab);
            }

            if (newTab != PackageFilterTab.UnityRegistry && m_PageManager.GetRefreshTimestamp(PackageFilterTab.UnityRegistry) == 0 && m_ApplicationProxy.isUpmRunning)
            {
                DelayRefresh(PackageFilterTab.UnityRegistry);
            }

            m_ExtensionManager.OnWindowCreated(this, packageDetails.extensionContainer, packageDetails.toolbar.extensions);
        }