diff --git a/gso/services/resource_manager.py b/gso/services/resource_manager.py
index b555c7c301a1c9d3445f85c9248d1ce13184679b..5c2424000ec6e7e7a743bd2aace8bcfa16c0d07e 100644
--- a/gso/services/resource_manager.py
+++ b/gso/services/resource_manager.py
@@ -1,6 +1,6 @@
 # mypy: ignore-errors
 from enum import Enum, auto
-from typing import List
+from typing import List, Set
 
 from gso import settings
 
@@ -23,8 +23,11 @@ def _dummy_router_interfaces(site_name) -> dict:
         "physical": [{"name": f"ifc-{x}", "state": InterfaceAllocationState.AVAILABLE} for x in range(250)],
     }
 
-
-_DUMMY_SITES = {"site-a", "site-b", "site-c"}
+_DUMMY_SITES = {
+    "site-a",
+    "site-b",
+    "site-c"
+}
 
 _DUMMY_INVENTORY = {
     "fqdn-a": _dummy_router_interfaces("site-a"),
@@ -32,7 +35,7 @@ _DUMMY_INVENTORY = {
     "fqdn-c": _dummy_router_interfaces("site-b"),
     "fqdn-d": _dummy_router_interfaces("site-b"),
     "fqdn-e": _dummy_router_interfaces("site-c"),
-    "fqdn-f": _dummy_router_interfaces("site-c"),
+    "fqdn-f": _dummy_router_interfaces("site-c")
 }
 
 
@@ -42,7 +45,10 @@ def import_new_site(new_site_name: str, oss_params=settings.OSSParams):
     _DUMMY_SITES.add(new_site_name)
 
 
-def import_new_router(new_router_fqdn: str, site_name: str, oss_params=settings.OSSParams):
+def import_new_router(
+        new_router_fqdn: str,
+        site_name: str,
+        oss_params=settings.OSSParams):
     # TODO: this is a dummy implementation
 
     # TODO: specify if this should be an error (and if not, what it means)
diff --git a/test/test_resource_manager.py b/test/test_resource_manager.py
index 37e26fe78cb8b6a1d68702994b824c38c63820aa..c809617d5f44d72465c0090c2ab4af298842d0e0 100644
--- a/test/test_resource_manager.py
+++ b/test/test_resource_manager.py
@@ -19,18 +19,24 @@ def test_new_site():
 
 
 def test_new_router():
+
     site_name = _random_string(10)
     resource_manager.import_new_site(new_site_name=site_name)
 
     router_name = _random_string(10)
     assert router_name not in resource_manager._DUMMY_INVENTORY
-    resource_manager.import_new_router(new_router_fqdn=router_name, site_name=site_name)
+    resource_manager.import_new_router(
+        new_router_fqdn=router_name,
+        site_name=site_name)
     assert router_name in resource_manager._DUMMY_INVENTORY
 
 
 def test_new_lag():
     router_name = list(resource_manager._DUMMY_INVENTORY.keys())[0]
-    new_lags = {resource_manager.next_lag(router_fqdn=router_name) for _ in range(10)}
+    new_lags = {
+        resource_manager.next_lag(router_fqdn=router_name)
+        for _ in range(10)
+    }
     assert len(new_lags) == 10
     assert new_lags <= set(resource_manager._DUMMY_INVENTORY[router_name]["lags"])