Update datastructures/graphs/undirected/clone_graph/__init__.py

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: BrianLusina

datastructures/graphs/undirected/clone_graph/__init__.py

@@ -20,7 +20,7 @@ def clone_helper(n: Optional[Node], nodes_cloned: Dict[Node, Node]) -> Optional[
             # This checks if the neighbour node neighbour has already been cloned.
             cloned_neighbour = nodes_cloned.get(neighbour)
             # If the neighbour is not cloned yet, recursively clone it
-            if not cloned_neighbour:
+            if cloned_neighbour is None:
                 cloned_node.neighbors += [clone_helper(neighbour, nodes_cloned)]
             # If the neighbour is already cloned, add the cloned neighbour to the new
             # node's neighbors