toJson method
Implementation
Map toJson(){
Map _result = {};
if (path != null) _result.addAll({"path": path});
if (url != null) _result.addAll({"url": url});
if (contentType != null) _result.addAll({"contentType": contentType});
if (id != null) _result.addAll({"id": id});
if (metadata != null) _result.addAll({"metadata": metadata});
if (createdAt != null) _result.addAll({"createdAt": createdAt});
return _result;
}