//creation of mailinglists
for(int i=0; i<NB_GROUP; i++) {
MailingList ml = new MailingList("mailinglist_" + i);
Collection users = ml.getUsers();
for(int j=0; j<NB_USER_PER_GROUP; j++) {
GroupUser u = new GroupUser("user_ml" + i + "_u" + j);
users.add(u);
}
Collection moderators = ml.getModerators();
for(int j=0; j<NB_USER_PER_GROUP; j++) {
GroupModerator gm = new GroupModerator("moderator_ml" + i, "mod" + j);