JavaScript to check if user is on a team 2016

Hi,

Basically I have a custom entity (e.g. a sector) that I want to limit access only to the owning team. I am able to get the ID and name of the team via JS with the getAttribute  & getValue functions on the "ownerid".

Where I am stuck is getting a list of the teams a user is on or getting a list of users ID's/names from a team. Either would work.

Are there any functions I can use to get these lists?

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What I have looked at/tried:

Microsoft says their "getUserRoles" function should list all roles and teams, but it definitely does not list all of the teams. (ID's don't match).

I've seen some support for this questions for 2011/13 but nothing for more recent editions. I also had some issues where some of the functions used in guides did not exist so it made me question if functionality changed a bit (think it was the requestheader function did not work). See: https://community.dynamics.com/crm/b/dynamicscrmpros/archive/2013/09/09/checking-if-a-user-is-a-member-of-a-team-using-javascript

https://social.microsoft.com/Forums/en-US/6f9ee6fb-2ce9-4e2e-8186-90be2bba9d36/get-all-the-teams-a-user-is-a-member-of?forum=crm

Does anyone know if these should still work for 2016? Any changes that could be made?