Update lowest_common_ancestor.py

Author: MaximSmolskiy

data_structures/binary_tree/lowest_common_ancestor.py

@@ -11,6 +11,10 @@ def swap(a: int, b: int) -> tuple[int, int]:
     Return a tuple (b, a) when given two integers a and b
     >>> swap(2,3)
     (3, 2)
+    >>> swap(3,4)
+    (4, 3)
+    >>> swap(67, 12)
+    (12, 67)
     >>> swap(3,-4)
     (-4, 3)
     """