How to add custom property object into User?

Hello everyone. I have a question. How we can add (not set) custom property?
For example: I have table: Users and table: timestamp. One user can have many timestamps (autoload is on).
I want to add timestamp into current list of timestamps that user already have.
Is there any way to retrieve relations from User table without using hashmaps ?


As Users is system table with some fields you cannot declare your own implementation of this class. But you can add some custom fileds to it. So that you can work with properties of User class as with hashmap only.
For your case you should find user, get property from retrieved object as list of related objects, add new object to this list and save entire User.