diff --git a/fitter.py b/fitter.py
index deed0eb..c55fc00 100644
--- a/fitter.py
+++ b/fitter.py
@@ -100,6 +100,7 @@ class Fitter:
     def optimize(self, init_parameters=None):
         t0 = time.time()
         self.iteration = 0
+
         if init_parameters is None:
             m = self.model()
             K_pc_half = m.K_pc_half
@@ -119,12 +120,12 @@ class Fitter:
         )
 
         res = least_squares(
-            self.cost_func, 
-            init_parameters, 
-            bounds=bounds, 
+            self.cost_func,
+            init_parameters,
+            bounds=bounds,
             xtol=1e-10,
-            ftol=1e-12,  
-            verbose=2
+            ftol=1e-12,
+            verbose=2,
         )
 
         print()