Fix flake8 B006 - Do not use mutable data structures for argument defaults

Author: luzfcb

custom_storages/storage.py

@@ -32,10 +32,13 @@ def get_comment_blocks(self, content):
             for match in re.finditer(r"\/\*.*?\*\/", content, flags=re.DOTALL)
         ]
 
-    def url_converter(self, name, hashed_files, template=None, comment_blocks=[]):
+    def url_converter(self, name, hashed_files, template=None, comment_blocks=None):
         """
         Return the custom URL converter for the given file name.
         """
+        if comment_blocks is None:
+            comment_blocks = []
+
         if template is None:
             template = self.default_template