in src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java [161:165]
private static GroupReference accountToGroup(AccountState s) {
AccountGroup.UUID uuid =
s.userName().isPresent() ? uuid(s.userName().get()) : uuid(s.account().id());
return GroupReference.create(uuid, nameOf(uuid, s));
}