refactor: improve test structure in mDNS tests

tests/discovery/mdns/test_utils.py

@@ -1,22 +1,22 @@
 """
 Basic unit tests for mDNS utils module.
 """
+
 import string
-import pytest
 
 from libp2p.discovery.mdns.utils import stringGen
 
 
 class TestStringGen:
-    """Basic unit tests for stringGen function."""
+    """Unit tests for stringGen function."""
 
     def test_stringgen_default_length(self):
         """Test stringGen with default length (63)."""
         result = stringGen()
-        
+
         assert isinstance(result, str)
         assert len(result) == 63
-        
+
         # Check that all characters are from the expected charset
         charset = string.ascii_lowercase + string.digits
         for char in result:
@@ -26,13 +26,13 @@ class TestStringGen:
         """Test stringGen with custom lengths."""
         # Test various lengths
         test_lengths = [1, 5, 10, 20, 50, 100]
-        
+
         for length in test_lengths:
             result = stringGen(length)
-            
+
             assert isinstance(result, str)
             assert len(result) == length
-            
+
             # Check that all characters are from the expected charset
             charset = string.ascii_lowercase + string.digits
             for char in result: