Author: Elliot Levin (elliotlevin@hotmail.com)
Inheritance: extends Iterator, implements Pinq\Iterators\IOrderedMap, use trait Pinq\Iterators\Common\OrderedMap
 protected function getInnerValuesIterator($outerKey, $outerValue)
 {
     $outerKeyFunction = $this->outerKeyFunction;
     $groupKey = $outerKeyFunction($outerValue, $outerKey);
     $traversableGroup = $this->constructInnerGroup($this->defaultIterator($this->innerGroups->contains($groupKey) && $groupKey !== null ? $this->innerGroups->get($groupKey) : new EmptyIterator()));
     return new ArrayIterator([$groupKey => $traversableGroup]);
 }
 protected function getInnerValuesIterator($outerKey, $outerValue)
 {
     $outerKeyFunction = $this->outerKeyFunction;
     $groupKey = $outerKeyFunction($outerValue, $outerKey);
     return $this->defaultIterator($this->innerGroups->contains($groupKey) && $groupKey !== null ? $this->innerGroups->get($groupKey) : new EmptyIterator());
 }