Add unit tests for MediaInfo frame class detection

- Created a JSON file containing various test cases for different video resolutions and their expected frame classes.
- Implemented a pytest test script that loads the test cases and verifies the frame class detection functionality of the MediaInfoExtractor.
- Utilized mocking to simulate the behavior of the MediaInfoExtractor and its video track attributes.

renamer/decorators/caching.py

@@ -15,7 +15,7 @@ def cached_method(ttl_seconds: int = 3600) -> Callable:
     """Decorator to cache method results with TTL.
 
     Caches the result of a method call using a global file-based cache.
-    The cache key includes class name, method name, and parameters hash.
+    The cache key includes class name, method name, instance identifier, and parameters hash.
 
     Args:
         ttl_seconds: Time to live for cached results in seconds (default 1 hour)
@@ -25,15 +25,18 @@ def cached_method(ttl_seconds: int = 3600) -> Callable:
     """
     def decorator(func: Callable) -> Callable:
         def wrapper(self, *args, **kwargs) -> Any:
-            # Generate cache key: class_name.method_name.param_hash
+            # Generate cache key: class_name.method_name.instance_id.param_hash
             class_name = self.__class__.__name__
             method_name = func.__name__
             
-            # Create hash from args and kwargs
+            # Use instance identifier (file_path for extractors)
+            instance_id = getattr(self, 'file_path', str(id(self)))
+            
+            # Create hash from args and kwargs (excluding self)
             param_str = json.dumps((args, kwargs), sort_keys=True, default=str)
             param_hash = hashlib.md5(param_str.encode('utf-8')).hexdigest()
             
-            cache_key = f"{class_name}.{method_name}.{param_hash}"
+            cache_key = f"{class_name}.{method_name}.{instance_id}.{param_hash}"
             
             # Try to get from cache
             cached_result = _cache.get_object(cache_key)