Change add to only add 1 leaf since that's what's really going on

anyways

pytreexo.py

@@ -30,16 +30,14 @@ def __str__(self):
     def __eq__(self, other):
         return self.roots == other.roots and self.numleaves == other.numleaves
 
-    def add(self, adds: [bytes]):
-        for add in adds:
-            for row in range(tree_rows(self.numleaves)+1):
-                if not root_present(self.numleaves, row):
-                    break
-                root = self.roots.pop()
-                add = parent_hash(root, add)
-
-            self.roots.append(add)
-            self.numleaves += 1
+    def add(self, add: bytes):
+        for row in range(tree_rows(self.numleaves)+1):
+            if not root_present(self.numleaves, row): break
+            root = self.roots.pop()
+            add = parent_hash(root, add)
+
+        self.roots.append(add)
+        self.numleaves += 1
 
     def verify(self, dels: [bytes], proof: Proof):
         if len(dels) != len(proof.targets):

tests/test_stump.py

@@ -13,7 +13,8 @@ def test_add(self):
                 hashed_leaves = [hashlib.sha256(leaf).digest() for leaf in leaves]
 
                 s = pytreexo.Stump()
-                s.add(hashed_leaves)
+                for hashed_leaf in hashed_leaves:
+                    s.add(hashed_leaf)
 
                 for i, expected_str in enumerate(test['expected_roots']):
                     expected = bytes.fromhex(expected_str)
@@ -50,7 +51,8 @@ def test_delete(self):
                 hashed_leaves = [hashlib.sha256(leaf).digest() for leaf in leaves]
 
                 s = pytreexo.Stump()
-                s.add(hashed_leaves)
+                for hashed_leaf in hashed_leaves:
+                    s.add(hashed_leaf)
 
                 preimages = [preimage.to_bytes(1, byteorder='big') for preimage in test['target_values']]
                 del_hashes = [hashlib.sha256(preimage).digest() for preimage in preimages]