hhvm/hphp/test/quick/UnsetM.php.expect

array(2) {
  [0]=>
  int(10)
  ["bye"]=>
  string(3) "BYE"
}
array(3) {
  [0]=>
  int(10)
  ["bye"]=>
  string(3) "BYE"
  ["foo"]=>
  int(29311)
}
array(2) {
  [0]=>
  int(10)
  ["bye"]=>
  string(3) "BYE"
}
array(0) {
}