diff --git a/payphone/core/utils.py b/payphone/core/utils.py
index a46f6ed..d361918 100644
--- a/payphone/core/utils.py
+++ b/payphone/core/utils.py
@@ -10,7 +10,8 @@ def deduplicate(i: Iterable[T], key: Callable[[T], U] = lambda i: i) -> list[T]:
 
     Args:
         i (Iterable[T]): The iterable with items to deduplicate.
-        key (Callable[[T], U], optional): The key by which to deduplicate. Defaults to `lambda i: i`.
+        key (Callable[[T], U], optional): The key by which to deduplicate. Defaults to
+          `lambda i: i`.
 
     Returns:
         list[T]: A list with the deduplicated items.
@@ -23,5 +24,5 @@ def deduplicate(i: Iterable[T], key: Callable[[T], U] = lambda i: i) -> list[T]:
     for item in i:
         if key(item) not in found_keys:
             result.append(item)
-    
+
     return result