diff --git a/examples/training/pomdp_solve/stopping_pomdp_defender/run_vs_random_attacker_v_001.py b/examples/training/pomdp_solve/stopping_pomdp_defender/run_vs_random_attacker_v_001.py
index c3f2628a7..292519ca5 100644
--- a/examples/training/pomdp_solve/stopping_pomdp_defender/run_vs_random_attacker_v_001.py
+++ b/examples/training/pomdp_solve/stopping_pomdp_defender/run_vs_random_attacker_v_001.py
@@ -1,5 +1,4 @@
 import numpy as np
-from gym_csle_stopping_game.dao.stopping_game_config import StoppingGameConfig
 from csle_common.metastore.metastore_facade import MetastoreFacade
 from gym_csle_stopping_game.util.stopping_game_util import StoppingGameUtil
 from csle_tolerance.util.pomdp_solve_parser import PomdpSolveParser
@@ -21,15 +20,16 @@
     simulation_env_config.simulation_env_input_config.stopping_game_config.L = 1
     simulation_env_config.simulation_env_input_config.stopping_game_config.O = list(range(10))
     simulation_env_config.simulation_env_input_config.stopping_game_config.Z = \
-        StoppingGameUtil.observation_tensor(n=10-1)
+        StoppingGameUtil.observation_tensor(n=10 - 1)
     gamma = 0.95
     pi2 = np.array([
         [0.9, 0.1],
         [1, 0],
         [1, 0]
     ])
-    pomdp_solve_file_str = StoppingGameUtil.pomdp_solver_file(config=simulation_env_config.simulation_env_input_config.stopping_game_config,
-                                       discount_factor=gamma, pi2=pi2)
+    pomdp_solve_file_str = StoppingGameUtil.pomdp_solver_file(
+        config=simulation_env_config.simulation_env_input_config.stopping_game_config,
+        discount_factor=gamma, pi2=pi2)
     with open("/home/kim/thesis/paper_1.pomdp", 'w') as f:
         f.write(pomdp_solve_file_str)
 
diff --git a/simulation-system/libs/gym-csle-stopping-game/src/gym_csle_stopping_game/util/stopping_game_util.py b/simulation-system/libs/gym-csle-stopping-game/src/gym_csle_stopping_game/util/stopping_game_util.py
index 6a502eb82..ebcc587b6 100644
--- a/simulation-system/libs/gym-csle-stopping-game/src/gym_csle_stopping_game/util/stopping_game_util.py
+++ b/simulation-system/libs/gym-csle-stopping-game/src/gym_csle_stopping_game/util/stopping_game_util.py
@@ -384,7 +384,5 @@ def pomdp_solver_file(config: StoppingGameConfig, discount_factor: float, pi2: n
                 for s_prime in config.S:
                     for o in config.O:
                         r = config.R[0][a1][0][s]
-                        file_str = (
-                                file_str + f"R: {a1} : {s} : {s_prime} : {o} {r:.80f}\n"
-                        )
+                        file_str = file_str + f"R: {a1} : {s} : {s_prime} : {o} {r:.80f}\n"
         return file_str