final Group centerForUpdate = this.groupRepository.findOneWithNotFoundDetection(centerId);
final Set<Group> groupMembers = assembleSetOfChildGroups(centerForUpdate.officeId(), command);
checkGroupMembersMeetingSyncWithCenterMeeting(centerId, groupMembers);
final Map<String, Object> actualChanges = new HashMap<>();
final List<String> changes = centerForUpdate.associateGroups(groupMembers);
if (!changes.isEmpty()) {
actualChanges.put(GroupingTypesApiConstants.groupMembersParamName, changes);
}
this.groupRepository.saveAndFlush(centerForUpdate);