- Output for 8.4.1 - 8.4.14
 - array(6) {
  [0]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    ["returned"]=>
    NULL
  }
  [1]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(4)
      ["c"]=>
      int(9)
    }
    ["returned"]=>
    NULL
  }
  [2]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(4)
      ["c"]=>
      int(9)
    }
    ["returned"]=>
    NULL
  }
  [3]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    ["returned"]=>
    NULL
  }
  [4]=>
  array(2) {
    ["yielded"]=>
    array(0) {
    }
    ["returned"]=>
    object(Generator)#4 (1) {
      ["function"]=>
      string(19) "test::firstIterator"
    }
  }
  [5]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    ["returned"]=>
    NULL
  }
}
 - Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.27
 - array(6) {
  [0]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    ["returned"]=>
    NULL
  }
  [1]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(4)
      ["c"]=>
      int(9)
    }
    ["returned"]=>
    NULL
  }
  [2]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(4)
      ["c"]=>
      int(9)
    }
    ["returned"]=>
    NULL
  }
  [3]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    ["returned"]=>
    NULL
  }
  [4]=>
  array(2) {
    ["yielded"]=>
    array(0) {
    }
    ["returned"]=>
    object(Generator)#4 (0) {
    }
  }
  [5]=>
  array(2) {
    ["yielded"]=>
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    ["returned"]=>
    NULL
  }
}