private object getData(IVoxelDataExtension ext, string field)
        {
            if (ext == null)
            {
                throw new InvalidOperationException();
            }
            var key = buildKey(ext, field);

            if (!data.ContainsKey(key))
            {
                data[key] = ReflectionHelper.GetDefaultValue(ext.GetType().GetProperty(field).PropertyType);
            }

            return(data[key]);
        }
 private string buildKey(IVoxelDataExtension ext, string field)
 {
     return(ext.GetType().Name + "-" + field);
     //return field;
 }