diff --git a/src/tree.py b/src/tree.py
index 74f8432..0591341 100644
--- a/src/tree.py
+++ b/src/tree.py
@@ -13,6 +13,9 @@ class Tree:
       return f"{leaf}"
     return "<empty>"
 
+  def is_leaf(self):
+    return self.left == None and self.right == None
+
 def build_tree(args):
   if args == None: 
     return None