private async Task DocumentClosed(IDocument doc)
{
var envs = _documentRegister.OpenDocuments.OfType <MapDocument>().Select(x => x.Environment).ToHashSet();
_resourceCollection.DisposeOtherEnvironments(envs);
if (_activeDocument.TryGetTarget(out var md) && md == doc)
{
await UpdateScene(null, null);
}
}