diff --git a/tests/unit_tests/tools/test_base.py b/tests/unit_tests/tools/test_base.py
index e79e3bb..c766bdc 100644
--- a/tests/unit_tests/tools/test_base.py
+++ b/tests/unit_tests/tools/test_base.py
@@ -2,38 +2,47 @@
 
 import numpy as np
 
-from choice_learn.toolbox.assortment_optimizer import MNLAssortmentOptimizer, LatentClassAssortmentOptimizer, LatentClassPricingOptimizer
+from choice_learn.toolbox.assortment_optimizer import (
+    LatentClassAssortmentOptimizer,
+    LatentClassPricingOptimizer,
+    MNLAssortmentOptimizer,
+)
 
 solvers = ["or-tools"]
 
+
 def test_mnl_assort_instantiate():
     """Test instantiation with both solvers."""
     for solv in solvers:
         MNLAssortmentOptimizer(
-        solver=solv,
-        utilities=np.array([1., 2., 3.]),
-        itemwise_values=np.array([0.5, 0.5, 0.5]),
-        assortment_size=2)
+            solver=solv,
+            utilities=np.array([1.0, 2.0, 3.0]),
+            itemwise_values=np.array([0.5, 0.5, 0.5]),
+            assortment_size=2,
+        )
 
 
 def test_lc_assort_instantiate():
     """Test instantiation with both solvers."""
     for solv in solvers:
         LatentClassAssortmentOptimizer(
-    solver=solv,
-    class_weights=np.array([.2, .8]),
-    class_utilities=np.array([[1., 2., 3.], [3., 2., 1.]]),
-    itemwise_values=np.array([0.5, 0.5, 0.5]),
-    assortment_size=2)
+            solver=solv,
+            class_weights=np.array([0.2, 0.8]),
+            class_utilities=np.array([[1.0, 2.0, 3.0], [3.0, 2.0, 1.0]]),
+            itemwise_values=np.array([0.5, 0.5, 0.5]),
+            assortment_size=2,
+        )
 
 
 def test_lc_pricing_instantiate():
     """Test instantiation with both solvers."""
     for solv in solvers:
         LatentClassPricingOptimizer(
-    solver=solv,
-    class_weights=np.array([.2, .8]),
-    class_utilities=np.array([[[1., 1.1], [2., 2.1], [3., 3.1]],
-    [[3., 3.1], [2., 2.1], [1., 1.1]]]),
-    itemwise_values=np.array([[0.5, 1.2], [0.5, 1.2], [0.5, 1.2]]),
-    assortment_size=2)
\ No newline at end of file
+            solver=solv,
+            class_weights=np.array([0.2, 0.8]),
+            class_utilities=np.array(
+                [[[1.0, 1.1], [2.0, 2.1], [3.0, 3.1]], [[3.0, 3.1], [2.0, 2.1], [1.0, 1.1]]]
+            ),
+            itemwise_values=np.array([[0.5, 1.2], [0.5, 1.2], [0.5, 1.2]]),
+            assortment_size=2,
+        )