array(3) {
  [1]=>
  array(1) {
    [0]=>
    int(2772)
  }
  [9]=>
  array(4) {
    [0]=>
    int(2880)
    [1]=>
    int(2903)
    [2]=>
    int(9247)
    [3]=>
    int(9294)
  }
  [21]=>
  array(1) {
    [0]=>
    int(9631)
  }
}