class Node(object):
    node.left
    key
    value
    node.right

@@ -3,12 +3,12 @@
 ass 
-Node
+Leaf
 (obj
@@ -21,45 +21,192 @@
     
-node.left%0A    key%0A    value%0A    node.
+'''Create leaf.'''%0A    def __init__(self, left=None, key=None, value=None, right=None):%0A        self.left = left%0A        self.key = key%0A        self.value = value%0A        self.right = 
 righ

create leaf class.