private void StartVisualTreeAssetTracking(ILiveReloadAssetTracker <VisualTreeAsset> tracker, VisualTreeAsset asset)
{
int dirtyCount = tracker.StartTrackingAsset(asset);
if (!m_AssetToTrackerMap.TryGetValue(asset, out var trackers))
{
trackers = new VisualTreeAssetToTrackMappingEntry()
{
m_LastDirtyCount = dirtyCount,
m_LastElementCount = asset.visualElementAssets.Count,
m_LastInlinePropertiesCount = asset.inlineSheet.rules.Sum(r => r.properties.Length),
m_LastAttributePropertiesDirtyCount = asset.GetAttributePropertiesDirtyCount(),
m_Trackers = new HashSet <ILiveReloadAssetTracker <VisualTreeAsset> >()
};
m_AssetToTrackerMap[asset] = trackers;
}
trackers.m_Trackers.Add(tracker);
}