Pop prefix.

src/re_classwise_shapley/cache.py

@@ -5,7 +5,7 @@
 
 class PrefixedMemcachedCacheBackend(MemcachedCacheBackend):
     def __init__(self, *args, **kwargs):
-        self._prefix = kwargs["prefix"]
+        self._prefix = kwargs.pop("prefix")
         super().__init__(*args, **kwargs)
 
     def get(self, key: str) -> Optional[Any]: