in service/src/main/java/org/apache/fineract/cn/group/internal/command/handler/GroupAggregate.java [268:277]
public String updateLeaders(final UpdateLeadersCommand updateLeadersCommand) {
this.groupRepository.findByIdentifier(updateLeadersCommand.identifier())
.ifPresent(groupEntity -> {
groupEntity.setLeaders(StringUtils.collectionToCommaDelimitedString(updateLeadersCommand.customerIdentifiers()));
groupEntity.setLastModifiedBy(UserContextHolder.checkedGetUser());
groupEntity.setLastModifiedOn(LocalDateTime.now(Clock.systemUTC()));
this.groupRepository.save(groupEntity);
});
return updateLeadersCommand.identifier();
}