Re-assign Primary Flag from Primary to Secondary Assignment using API

Hi Team, I was able to create a Secondary Employee Assignment using the API "hr_assignment_api.create_secondary_emp_asg" and he/she was assigned an Assignment Number of "22222-2".

My next Step would be to make "22222-2" the primary assignment instead of "22222". I can do this from the front-end but how do i do this from the API? I'm running through the "hr_assignment_api" package but i can't seem to find any API related to updating of Primary Assignments.

Oracle EBS 12.1.3

Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

PL/SQL Release 11.2.0.4.0 - Production

"CORE 11.2.0.4.0 Production"