Description:
------------
I tried to loop through a SplMaxHeap object multiple times but it only loops once. As there is no option to reset or rewind the heap object I don't see a way to loop through it multiple times.

I noticed that $heap->count() decreases with every loop cycle, perhaps that is the reason.

Test script:
---------------
$heap = new SplMaxHeap();
$heap->insert(1);
$heap->insert(2);
foreach($heap as $number){
  echo $number."\n";
}
foreach($heap as $number){
  echo $number."\n";
}



Expected result:
----------------
2
1
2
1


Actual result:
--------------
2
1