private static void AddMetaData(BsonDocument document, BundleEntry entry)
{
document[Field.VERSIONID] = entry.Links.SelfLink.ToString();
document[Field.ENTRYTYPE] = entry.TypeName();
document[Field.COLLECTION] = entry.GetResourceTypeName();
document[Field.VERSIONDATE] = GetVersionDate(entry) ?? DateTime.UtcNow;
}