Improve ChangeStreamIterator handling of wrapped iterator

Author: alcaeus

src/ChangeStream.php

@@ -18,7 +18,6 @@
 namespace MongoDB;
 
 use Iterator;
-use MongoDB\Driver\Cursor;
 use MongoDB\Driver\CursorId;
 use MongoDB\Driver\Exception\ConnectionException;
 use MongoDB\Driver\Exception\RuntimeException;
@@ -29,7 +28,6 @@
 use MongoDB\Model\ChangeStreamIterator;
 use ReturnTypeWillChange;
 
-use function assert;
 use function call_user_func;
 use function in_array;
 
@@ -116,10 +114,7 @@ public function current()
      */
     public function getCursorId()
     {
-        $cursor = $this->iterator->getInnerIterator();
-        assert($cursor instanceof Cursor);
-
-        return $cursor->getId();
+        return $this->iterator->getInnerIterator()->getId();
     }
 
     /**

src/Model/ChangeStreamIterator.php

@@ -30,6 +30,7 @@
 use MongoDB\Exception\UnexpectedValueException;
 use ReturnTypeWillChange;
 
+use function assert;
 use function count;
 use function is_array;
 use function is_object;
@@ -44,7 +45,6 @@
  * rewind() do not execute getMore commands.
  *
  * @internal
- * @method Cursor getInnerIterator()
  */
 class ChangeStreamIterator extends IteratorIterator implements CommandSubscriber
 {
@@ -135,6 +135,14 @@ public function current()
         return $this->isValid ? parent::current() : null;
     }
 
+    final public function getInnerIterator(): Cursor
+    {
+        $cursor = parent::getInnerIterator();
+        assert($cursor instanceof Cursor);
+
+        return $cursor;
+    }
+
     /**
      * Returns the resume token for the iterator's current position.
      *