Update decorators.py

key_builder now receives wrapped function as first argument

aiocache/decorators.py

@@ -87,7 +87,7 @@ def get_cache_key(self, f, args, kwargs):
         if self.key:
             return self.key
         if self.key_builder:
-            return self.key_builder(*args, **kwargs)
+            return self.key_builder(f, *args, **kwargs)
 
         return self._key_from_args(f, args, kwargs)