diff --git a/tests/unit/mixin/test_preview.py b/tests/unit/mixin/test_preview.py
index e6c1f11e..35beeeb0 100644
--- a/tests/unit/mixin/test_preview.py
+++ b/tests/unit/mixin/test_preview.py
@@ -179,12 +179,10 @@ def Branched(x) -> bool:
         with self.subTest("Uninspectable function"):
 
             def _uninspectable():
-                template = dedent(
-                    """
+                template = dedent("""
                     def __source_code_not_available(x):
                         return x
-                    """
-                )
+                    """)
                 scope = {}
                 exec(template, {}, scope)
                 return scope["__source_code_not_available"]