array(3) {
  [0]=>
  array(1) {
    ["isPremium"]=>
    array(2) {
      ["order"]=>
      string(4) "desc"
      ["missing"]=>
      int(0)
    }
  }
  ["level"]=>
  array(1) {
    ["order"]=>
    string(3) "asc"
  }
  ["_score"]=>
  array(1) {
    ["order"]=>
    string(4) "desc"
  }
}