static FieldInfo GetDecoderField(BitmapDecoder decoder, string fieldName)
        {
            FieldInfo streamField = decoder.GetType().GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Instance);

            if (streamField == null)
            {
                throw new Exception(string.Format("{0}.{1} ({2})", decoder.GetType().FullName, fieldName, decoder.GetType().AssemblyQualifiedName));
            }
            return(streamField);
        }