array(3) {
  [1]=>
  array(1) {
    [0]=>
    int(2772)
  }
  [9]=>
  array(4) {
    [0]=>
    int(2865)
    [1]=>
    int(7117)
    [2]=>
    int(7546)
    [3]=>
    int(7836)
  }
  [21]=>
  array(1) {
    [0]=>
    int(9641)
  }
}