Add signature to cached property function

diff --git a/wg-mullvad.py b/wg-mullvad.py
index 84eefdc4b3fa9280d4c3c6168d774df8c4775ed5..39268b39abfca21c0d6748453d0ae0893be468bc 100755 (executable)
--- a/wg-mullvad.py
+++ b/wg-mullvad.py
@@ -57,7 +57,7 @@ class MullvadApi:
         return self._api(f'{MullvadApi.HOST}/accounts/v1/devices')
 
     @functools.cached_property
-    def web_token(self):
+    def web_token(self) -> str:
         body = {
             'account_number': self.account_number,
         }