List<OrganizationalEntity> list = new ArrayList<OrganizationalEntity>(size);
for ( int i = 0; i < size; i++ ) {
short type = in.readShort();
if ( type == 0 ) {
User user = new User();
user.readExternal( in );
list.add( user );
} else {
Group group = new Group();
group.readExternal( in );
list.add( group );