Question

according to the documentation the model should be like this

public class Employee
{
  @Id String name;
  Key<Employee>[] subordinates;
}

I need to know how can I add subordinates to an Employee.

Answer 1

A better approach would probably be for each Subordinate entity, to have a property with its manager, like this:

public class Employee {
    @Id
    String name;

    Key<Employee> manager;
}

In any case, if you still want to have a list of subordinates in each Employee entity, first you get the entity, you add the Key of the subordinate to the list, and you save the entity.

Hope this helps.