Untitled

array(2) {
  [0]=>
  string(3) "bot"
  [1]=>
  string(5) "sysop"
}
array(2) {
  [0]=>
  string(3) "bot"
  [1]=>
  string(5) "sysop"
}
array(0) {
}

FROM

                var_dump($oldGroups);
                var_dump($newGroups);
                var_dump($addedGroups);