public void WriteTo(string path)
 {
     using (var writer = new StreamWriter(path))
     {
         ObjFileWriter.Write(this, writer);
     }
 }
        public void WriteTo(Stream stream)
        {
            if (stream == null)
            {
                throw new ArgumentNullException("stream");
            }

            using (var writer = new StreamWriter(stream))
            {
                ObjFileWriter.Write(this, writer);
            }
        }