public void SerializeProperty(
BsonWriter bsonWriter,
object obj,
BsonPropertyMap propertyMap
)
{
var value = (BsonTimestamp) propertyMap.Getter(obj);
if (value == null) {
bsonWriter.WriteNull(propertyMap.ElementName);
} else {
bsonWriter.WriteTimestamp(propertyMap.ElementName, value.Value);
}
}