Do not use a mutable data structure for argument default
@@ -731,7 +731,10 @@ class _ShelfCacheBackend(object):
class _Request(object):
"""Representing an abstract web service operation."""
- def __init__(self, network, method_name, params={}):
+ def __init__(self, network, method_name, params=None):
+
+ if params is None:
+ params = {}
self.network = network
self.params = {}
