private void SetupUI()
        {
            var styleSheet = AssetDatabase.LoadAssetAtPath <StyleSheet>($"{Utils.packageFolderName}/Editor/StyleSheets/PerformanceTrackerWindow.uss");

            rootVisualElement.styleSheets.Add(styleSheet);

            m_RefreshFromSearch = Delayer.Throttle(RefreshFromSearch);

            var toolbar = new UnityEditor.UIElements.Toolbar();

            toolbar.AddToClassList("perf-toolbar");
            toolbar.style.height = PtStyles.itemHeight;

            var searchBox = new VisualElement();

            searchBox.AddToClassList("perf-search-box");
            AddSelectorLabel(toolbar, "Tracker");
            m_SearchField = new ToolbarSearchField();
            m_SearchField.AddToClassList("perf-search-tracker");
            m_SearchField.value = m_FilterText;
            m_SearchField.RegisterCallback <ChangeEvent <string> >((evt) =>
            {
                m_RefreshFromSearch.Execute(evt.newValue);
            });
            searchBox.Add(m_SearchField);
            toolbar.Add(searchBox);

            var resetAllCountersButton = new Button(ResetAllCounters);

            resetAllCountersButton.text = "Reset all counters";
            resetAllCountersButton.AddToClassList("perf-tracker-toolbar-button");
            toolbar.Add(resetAllCountersButton);

            AddSelectorLabel(toolbar, "Update Speed");
            var choices             = PtModel.RefreshRates.Select(r => r.label).ToList();
            var updateSpeedSelector = new UnityEditor.UIElements.PopupField <string>(choices, 0);

            updateSpeedSelector.value = PtModel.RefreshRates[m_UpdateSpeedIndex].label;
            updateSpeedSelector.AddToClassList("perf-update-speed-selector");
            updateSpeedSelector.RegisterCallback <ChangeEvent <string> >((evt) =>
            {
                m_UpdateSpeedIndex = Array.FindIndex(PtModel.RefreshRates, (r) => r.label == evt.newValue);
                ScheduleNextRefresh();
                SendAnalytics(Analytics.WindowUsageType.ChangeMonitoringSpeed);
            });
            toolbar.Add(updateSpeedSelector);

            AddSelectorLabel(toolbar, "Columns");
            var columnsChoice   = PtModel.ColumnDescriptors.Where(desc => desc.columnsSelectorMaskId > 0).Select(desc => desc.label).ToList();
            var columnsSelector = new MaskField(columnsChoice, m_ShownColumn);

            columnsSelector.RegisterCallback <ChangeEvent <int> >((evt) =>
            {
                m_ShownColumn = evt.newValue;
                CreateHeaders();
                RefreshTrackers();
                SendAnalytics(Analytics.WindowUsageType.ChangeColumnLayout);
            });
            columnsSelector.AddToClassList("perf-columns-selector");
            toolbar.Add(columnsSelector);

            AddSelectorLabel(toolbar, "Sort By");
            m_SortBySelector       = new EnumField(ColumnId.Name);
            m_SortBySelector.value = m_SortBy;
            m_SortBySelector.AddToClassList("perf-sort-by-selector");
            m_SortBySelector.RegisterCallback <ChangeEvent <Enum> >((evt) =>
            {
                ChangeSortOrder((ColumnId)evt.newValue);
                SendAnalytics(Analytics.WindowUsageType.ChangeSortBy);
            });
            toolbar.Add(m_SortBySelector);

            var settingsBtn = new Button(() =>
            {
                SettingsService.OpenUserPreferences(PerformanceTrackerSettings.settingsKey);
                SendAnalytics(Analytics.WindowUsageType.OpenPreferences);
            });

            settingsBtn.style.backgroundImage = Icons.settings;
            settingsBtn.style.width           = PtStyles.itemHeight - 3;
            settingsBtn.style.height          = PtStyles.itemHeight - 3;

            toolbar.Add(settingsBtn);

            rootVisualElement.Add(toolbar);

            // Set List View Header:
            m_HeaderRow = new VisualElement();
            m_HeaderRow.AddToClassList("perf-header-row-container");
            m_HeaderRow.style.flexDirection = FlexDirection.Row;
            rootVisualElement.Add(m_HeaderRow);
            CreateHeaders();

            m_PinnedTrackersView      = new ListView(m_PinnedTrackers, PtStyles.itemHeight, MakeItem, BindPinnedItem);
            m_PinnedTrackersView.name = k_PinnedTrackerList;
            m_PinnedTrackersView.AddToClassList("perf-tracker-list");
            m_PinnedTrackersView.selectionType  = SelectionType.Multiple;
            m_PinnedTrackersView.style.flexGrow = 0;
            m_PinnedTrackersView.Q <VisualElement>(null, "unity-scroll-view__content-viewport").RegisterCallback <GeometryChangedEvent>(SyncHeaderAndListsGeometry);
            rootVisualElement.Add(m_PinnedTrackersView);

            m_TrackersView      = new ListView(m_FilteredTrackers, PtStyles.itemHeight, MakeItem, BindUnpinnedItem);
            m_TrackersView.name = k_TrackerList;
            m_TrackersView.AddToClassList("perf-tracker-list");
            m_TrackersView.selectionType  = SelectionType.Multiple;
            m_TrackersView.style.flexGrow = 1.0f;

            m_TrackersView.Q <VisualElement>(null, "unity-scroll-view__content-viewport").RegisterCallback <GeometryChangedEvent>(SyncHeaderAndListsGeometry);

            rootVisualElement.Add(m_TrackersView);

            m_NeedsUpdate = true;
            ScheduleNextRefresh();
            UpdateTrackers();
        }