```diff
--- test_files/382-original.txt	2025-03-07 19:06:52
+++ test_files/382-modified.txt	2025-03-07 19:06:52
@@ -3,8 +3,20 @@
 from importlib.metadata import PackageNotFoundError, metadata
 
 
+_installed = set()
+
+
 def check_if_package_is_intalled(name: str) -> bool:
     try:
-        return bool(metadata(name))
+        return name in _installed or bool(metadata(name))
     except PackageNotFoundError:
         return False
+
+
+def add_package_to_installed_list(name: str):
+    _installed.add(name)
+
+
+# This for testing purposes
+def reset_installed_list():
+    _installed.clear()
```
