Add missing monkeypatch method for unit tests

Author: shayancanonical

tests/unit/conftest.py

@@ -77,8 +77,10 @@ def start(self, services: list[str] = None, *_, **__):
             for service in services:
                 assert service in ("mysqlrouter-service", "mysqlrouter-exporter")
 
-            self.services["mysqlrouter-service"]["active"] = "mysqlrouter-service" in services
-            self.services["mysqlrouter-exporter"]["active"] = "mysqlrouter-exporter" in services
+            if "mysqlrouter-service" in services:
+                self.services["mysqlrouter-service"]["active"] = True
+            if "mysqlrouter-exporter" in services:
+                self.services["mysqlrouter-exporter"]["active"] = True
 
         def stop(self, services: list[str] = None, *_, **__):
             for service in services:
@@ -89,6 +91,12 @@ def stop(self, services: list[str] = None, *_, **__):
             if "mysqlrouter-exporter" in services:
                 self.services["mysqlrouter-exporter"]["active"] = False
 
+        def restart(self, services: list[str] = []):
+            if "mysqlrouter-service" in services:
+                self.services["mysqlrouter-service"]["active"] = True
+            if "mysqlrouter-exporter" in services:
+                self.services["mysqlrouter-exporter"]["active"] = True
+
     monkeypatch.setattr(snap, "_snap", Snap())
 
     monkeypatch.setattr(