code: public List<OrganizationMembership> getOrganizationMembershipByUser(long user_id) {
  	return complete(submit(req("GET", tmpl("/users/{user_id}/organization_memberships.json").set("user_id", user_id)),
  		handleList(OrganizationMembership.class, "organization_memberships")));
      }
docs: https://support.zendesk.com/hc/communities/public/posts/203464106-Managing-Organization-Memberships-via-the-Zendesk-API