diff --git a/src/blackbox/blackbox_factory.py b/src/blackbox/blackbox_factory.py
index d46e07b..35e0fad 100644
--- a/src/blackbox/blackbox_factory.py
+++ b/src/blackbox/blackbox_factory.py
@@ -7,7 +7,6 @@ from blackbox.text_to_audio import TextToAudio
 class BlackboxFactory:
 
     def create_blackbox(self, blackbox_type: str, blackbox_config: dict) -> Blackbox:
-        
         if blackbox_type == "audio_to_text":
             return AudioToText(blackbox_config)
         if blackbox_type == "text_to_audio":
diff --git a/src/blackbox/calculator.py b/src/blackbox/calculator.py
index 51cd658..b9ad352 100644
--- a/src/blackbox/calculator.py
+++ b/src/blackbox/calculator.py
@@ -4,12 +4,12 @@ from blackbox.blackbox import Blackbox
 
 
 class Calculator(Blackbox):
-    
-    """This class just for example, it show how to implement Blackbox interface."""
 
+    """This class just for example, it show how to implement Blackbox interface."""
+    
     def valid(self, data: any) -> bool:
         return isinstance(data, dict) and "op" in data and "left" in data and "right" in data
-    
+
     def processing(self, data: dict) -> any:
         if not self.valid(data):
             raise ValueError("Invalid data")
diff --git a/src/blackbox/text_to_audio.py b/src/blackbox/text_to_audio.py
index 9881d17..abea26e 100644
--- a/src/blackbox/text_to_audio.py
+++ b/src/blackbox/text_to_audio.py
@@ -5,6 +5,7 @@ from gtts import gTTS
 from io import BytesIO
 
 class TextToAudio(Blackbox):
+    
     def valid(self, data: any) -> bool:
         return isinstance(data, str)