array(3) {
  [0]=>
  string(1) "a"
  [1]=>
  string(1) "b"
  [2]=>
  string(1) "c"
}
array(2) {
  [0]=>
  string(1) "a"
  [1]=>
  string(1) "c"
}
array(1) {
  [0]=>
  string(1) "a"
}