/// <summary>
        /// Serialize a geometry
        /// </summary>
        /// <param name="geometry">geometry</param>
        /// <returns>byte[]</returns>
        private static byte[] Serialize(Geometry.Geometry geometry)
        {
            byte[] bytes;
            using (var buffer = new BsonBuffer())
            {
                using (var bsonWriter = BsonWriter.Create(buffer))
                {
                    BsonSerializer.Serialize(bsonWriter, geometry);
                }
                bytes = buffer.ToByteArray();
            }

            return bytes;
        }