Retrieve personal distribution lists after a specified time
    You can retrieve all of a user's personal distribution lists that were
        created or edited after a time that you specify. In the following sample code, 
BEMS
 retrieves the personal
        distribution lists that were created and updated in the user's mailbox after the SinceTs of
        1489762857000.POST /api/contactgroup HTTP/1.1 https://:<BEMS FQDN>:8443/api/contactgroup Content-Type: application/json X-Good-GD-AuthToken: <GDAuthToken> { "SinceTs": 1489762857000 }
If the request is successful, 
BEMS
 returns the following
        responses and the BlackBerry Work
 and
        third-party apps display the user's updated personal distribution lists. - If the distribution list did not change after the specified SinceTs,BEMSreturns the following response:HTTP/1.1 200 OK {}
- If the distribution list did change after the specified SinceTs,BEMSreturns the following reponse:In the response example, distribution list 2 adds a new, and distribution list 3 removes a contact.HTTP/1.1 200 OK { Groups:[ {Name: "<personal distribution_list2>", Members: [ {Name: "<User1>", Email: "<user1@example.com>"}, {Name: "<User2>", Email: "<user2@example.com>"}, {Name: "<User3>", Email: "<user3@example.com>"}, {Name: "<User4>", Email: "<user4@example.com>"} ] }, {Name: "<personal distribution_list3>", Members: [ {Name: "<User1>", Email: "<user1@example.com>"}, {Name: "<User2>", Email: "<user2@example.com>"}, {Name: "<User3>", Email: "<user3@example.com>"} ] } ] }