diff --git a/grid5000/objects.py b/grid5000/objects.py
index 54a566c1e5d990ce29d9d7fa3b6ba8f1445d59d9..d3ebca3fe9e26e4de8a4d2c3c878dcb8aba5da80 100644
--- a/grid5000/objects.py
+++ b/grid5000/objects.py
@@ -5,6 +5,7 @@ from .mixins import *  # noqa
 class FirewallPort(RESTObject):
     _id_attr = None
 
+
 class NetworkEquipment(RESTObject):
     pass
 
@@ -74,12 +75,10 @@ class Cluster(RESTObject):
 
 class Job(RESTObject, RefreshMixin, ObjectDeleteMixin):
     _create_attrs = (("command"),)
-
-    _managers=(
+    _managers = (
         ("firewall", "SiteJobFirewallManager"),
     )
 
-
     def __repr__(self):
         keys = ["uid", "site", "state", "user"]
         try:
@@ -142,6 +141,8 @@ class JobManager(NoUpdateMixin, BracketMixin, RESTManager):
     _path = "/sites/%(site)s/jobs"
     _obj_cls = Job
     _from_parent_attrs = {"site": "uid"}
+
+
 class ClusterManager(RetrieveMixin, BracketMixin, RESTManager):
     _path = "/sites/%(site)s/clusters"
     _obj_cls = Cluster
@@ -396,4 +397,4 @@ class SiteJobFirewallManager(ListMixin, DeleteMixin, CreateMixin, RESTManager):
 
         # Handle specific URL for creation
         server_data = self.grid5000.http_post(self.path, post_data=data, **kwargs)
-        return [self._obj_cls(self, s) for s in server_data]
\ No newline at end of file
+        return [self._obj_cls(self, s) for s in server_data]