public string ExtractEntities(IMap map, IEnumerable<string> entityNames)
 {
     Dictionary<string, object> root = new Dictionary<string, object>();
     root["Entities"] = map.GetEntitiesWithName(entityNames);
     root["Layers"] = map.Layers;
     root["ExtractedEntities"] = entityNames;
     return JsonConvert.SerializeObject(root, Formatting.Indented);
 }