diff --git a/guesthouse/chproxy.py b/guesthouse/chproxy.py
index 6af72f8..d28d352 100644
--- a/guesthouse/chproxy.py
+++ b/guesthouse/chproxy.py
@@ -7,6 +7,7 @@
 from yaml import Dumper, Loader
 
 
+# A line of comment.
 class ChProxy:
     def __init__(self, chproxy_path: Path, template_path: Path, user_prefix: str):
         self.config_dir = TemporaryDirectory()