array(2) {
  [1]=>
  int(1)
  [2]=>
  &int(2)
}
array(4) {
  [1]=>
  int(1)
  [2]=>
  &int(2)
  [3]=>
  int(3)
  [4]=>
  &int(4)
}
array(2) {
  [3]=>
  int(3)
  [4]=>
  &int(4)
}