/**
  * @param $group
  * @return GroupUserMembershipForm
  */
 public static function makeFormFromGroup($group)
 {
     assert('$group instanceof Group');
     $form = new GroupUserMembershipForm();
     $userMembershipData = GroupUserMembershipFormUtil::makeUserMembershipDataFromUsers($group->users);
     $userNonMembershipData = GroupUserMembershipFormUtil::makeNonUserMembershipDataFromUserMembershipData($userMembershipData);
     $form->userMembershipData = $userMembershipData;
     $form->userNonMembershipData = $userNonMembershipData;
     return $form;
 }