diff --git a/backive/core/backup.py b/backive/core/backup.py
index 034e42f..dff375a 100644
--- a/backive/core/backup.py
+++ b/backive/core/backup.py
@@ -47,7 +47,7 @@ class Backup:
             user = self.config.get("user")
             proc = await asyncio.create_subprocess_shell(
 #                "set -x; chown -R {} ${{BACKIVE_MOUNT}}/${{BACKIVE_TO}};".format(user) +
-#                "sudo -E -u {} sh -c '".format(user) + 
+#                "sudo -E -u {} sh -c '".format(user) +
                 self.config.get("script"),
 #                "'",
                 stdout=asyncio.subprocess.PIPE,
diff --git a/backive/core/events.py b/backive/core/events.py
index 5b04a76..7466dc7 100644
--- a/backive/core/events.py
+++ b/backive/core/events.py
@@ -1,3 +1,7 @@
+"""
+TODO
+"""
+
 import os
 import asyncio
 
diff --git a/backive/core/scheduler.py b/backive/core/scheduler.py
index 7fffec1..529b0d7 100644
--- a/backive/core/scheduler.py
+++ b/backive/core/scheduler.py
@@ -5,6 +5,9 @@ from datetime import datetime
 
 
 class Scheduler():
+    """
+    TODO
+    """
     __shared_state = dict()
     __data = dict()
     def __init__(self):
diff --git a/backive/core/tool.py b/backive/core/tool.py
index 8b11c4a..f3946db 100644
--- a/backive/core/tool.py
+++ b/backive/core/tool.py
@@ -4,6 +4,9 @@ import os
 AVAILABLE_TOOLS = {}
 
 def register_tool(name):
+    """
+    TODO
+    """
     def decorator(Cls):
         AVAILABLE_TOOLS.update({name: Cls})
     return decorator
diff --git a/backive/tools/rsync.py b/backive/tools/rsync.py
index 9dd25f4..813ecf1 100644
--- a/backive/tools/rsync.py
+++ b/backive/tools/rsync.py
@@ -3,5 +3,8 @@ from backive.core.tool import AVAILABLE_TOOLS, register_tool
 
 @register_tool("rsync")
 class Rsync:
+    """
+    TODO
+    """
     def __init__(self, options):
         pass
diff --git a/tests/test_events.py b/tests/test_events.py
index 941c37a..2a387be 100644
--- a/tests/test_events.py
+++ b/tests/test_events.py
@@ -10,6 +10,9 @@ from backive.core.events import EventInterface
 
 
 class TestEvents(unittest.TestCase):
+    """
+    TODO
+    """
     def set_data(self, data):
         self.data = data