Use the following samples to create a application that will add a user to a group.
CommandExample.java and SearchCommandExample.java.
Create and save the user as shown in CommandExample.java.
Use SearchCommandExample.java to find the UserDTO you just created.
Use a modified SearchSommandExample.java to create a SearchUserGroupCommand to find an existing group. This will get you a UserGroupDTO
Create an AddChildUserCommand using the two DTO objects just created.