Minor change - Update operations.

src/Operation/Count.php

@@ -18,6 +18,6 @@ final class Count extends Operation
      */
     public function run(BaseCollectionInterface $collection)
     {
-        return \iterator_count($collection->getIterator());
+        return \iterator_count($collection);
     }
 }

src/Operation/Filter.php

@@ -27,7 +27,7 @@ public function run(BaseCollectionInterface $collection): BaseCollectionInterfac
         return $collection::with(
             static function () use ($callbacks, $collection): \Generator {
                 foreach ($callbacks as $callback) {
-                    foreach ($collection->getIterator() as $key => $value) {
+                    foreach ($collection as $key => $value) {
                         if (true === (bool) $callback($value, $key)) {
                             yield $key => $value;
                         }

src/Operation/Flatten.php

@@ -30,9 +30,7 @@ public function run(BaseCollectionInterface $collection): BaseCollectionInterfac
 
         return $collection::with(
             static function () use ($depth, $collection): \Generator {
-                $iterator = $collection->getIterator();
-
-                foreach ($iterator as $item) {
+                foreach ($collection as $item) {
                     if (!\is_array($item) && !$item instanceof BaseCollectionInterface) {
                         yield $item;
                     } elseif (1 === $depth) {

src/Operation/Last.php

@@ -18,16 +18,12 @@ final class Last extends Operation
      */
     public function run(BaseCollectionInterface $collection)
     {
-        /** @var \Iterator $iterator */
-        $iterator = $collection->getIterator();
-
-        $last = $iterator->current();
-
-        while (true === $iterator->valid()) {
-            $last = $iterator->current();
-            $iterator->next();
-        }
-
-        return $last;
+        return (
+        new Reduce(
+            static function ($carry, $item) {
+                return $item;
+            },
+            $collection->getIterator()->current()
+        ))->run($collection);
     }
 }

src/Operation/Rebase.php

@@ -16,6 +16,6 @@ final class Rebase extends Operation
      */
     public function run(BaseCollectionInterface $collection): BaseCollectionInterface
     {
-        return $collection::with($collection->getIterator());
+        return $collection::with($collection);
     }
 }

src/Operation/Sort.php

@@ -33,7 +33,7 @@ public function run(BaseCollectionInterface $collection): BaseCollectionInterfac
 
         return $collection::with(
             static function () use ($callback, $collection): \Generator {
-                $array = \iterator_to_array($collection->getIterator());
+                $array = \iterator_to_array($collection);
 
                 \uasort($array, $callback);