prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Cannot list package files
  ## Description of the problem, including code/CLI snippet
  
  [Listing package files](https://docs.gitlab.com/ee/api/packages.html#list-package-files) appears to be unsupported. The API endpoint was introduced in GitLab 11.8.
  
  ## Expected Behavior
  
  Listing package files should be possible.
  
  ## Actual Behavior
  
  Listing package files is not possible.
  
  ## Specifications
  
    - python-gitlab version: 2.6.0
    - API version you are using (v3/v4): v4
    - Gitlab server version (or gitlab.com): gitlab.com
  
  
  PR incoming.
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `gitlab/v4/objects/packages.py`
  Content:
  ```
  1 from gitlab.base import RESTManager, RESTObject
  2 from gitlab.mixins import DeleteMixin, GetMixin, ListMixin, ObjectDeleteMixin
  3 
  4 
  5 __all__ = [
  6     "GroupPackage",
  7     "GroupPackageManager",
  8     "ProjectPackage",
  9     "ProjectPackageManager",
  10 ]
  11 
  12 
  13 class GroupPackage(RESTObject):
  14     pass
  15 
  16 
  17 class GroupPackageManager(ListMixin, RESTManager):
  18     _path = "/groups/%(group_id)s/packages"
  19     _obj_cls = GroupPackage
  20     _from_parent_attrs = {"group_id": "id"}
  21     _list_filters = (
  22         "exclude_subgroups",
  23         "order_by",
  24         "sort",
  25         "package_type",
  26         "package_name",
  27     )
  28 
  29 
  30 class ProjectPackage(ObjectDeleteMixin, RESTObject):
  31     pass
  32 
  33 
  34 class ProjectPackageManager(ListMixin, GetMixin, DeleteMixin, RESTManager):
  35     _path = "/projects/%(project_id)s/packages"
  36     _obj_cls = ProjectPackage
  37     _from_parent_attrs = {"project_id": "id"}
  38     _list_filters = (
  39         "order_by",
  40         "sort",
  41         "package_type",
  42         "package_name",
  43     )
  44
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/gitlab/v4/objects/packages.py b/gitlab/v4/objects/packages.py
  --- a/gitlab/v4/objects/packages.py
  +++ b/gitlab/v4/objects/packages.py
  @@ -1,12 +1,13 @@
   from gitlab.base import RESTManager, RESTObject
   from gitlab.mixins import DeleteMixin, GetMixin, ListMixin, ObjectDeleteMixin
   
  -
   __all__ = [
       "GroupPackage",
       "GroupPackageManager",
       "ProjectPackage",
       "ProjectPackageManager",
  +    "ProjectPackageFile",
  +    "ProjectPackageFileManager",
   ]
   
   
  @@ -28,7 +29,7 @@
   
   
   class ProjectPackage(ObjectDeleteMixin, RESTObject):
  -    pass
  +    _managers = (("package_files", "ProjectPackageFileManager"),)
   
   
   class ProjectPackageManager(ListMixin, GetMixin, DeleteMixin, RESTManager):
  @@ -41,3 +42,13 @@
           "package_type",
           "package_name",
       )
  +
  +
  +class ProjectPackageFile(RESTObject):
  +    pass
  +
  +
  +class ProjectPackageFileManager(ListMixin, RESTManager):
  +    _path = "/projects/%(project_id)s/packages/%(package_id)s/package_files"
  +    _obj_cls = ProjectPackageFile
  +    _from_parent_attrs = {"project_id": "project_id", "package_id": "id"}
  
verification_info: {"golden_diff": "diff --git a/gitlab/v4/objects/packages.py b/gitlab/v4/objects/packages.py\n--- a/gitlab/v4/objects/packages.py\n+++ b/gitlab/v4/objects/packages.py\n@@ -1,12 +1,13 @@\n from gitlab.base import RESTManager, RESTObject\n from gitlab.mixins import DeleteMixin, GetMixin, ListMixin, ObjectDeleteMixin\n \n-\n __all__ = [\n     \"GroupPackage\",\n     \"GroupPackageManager\",\n     \"ProjectPackage\",\n     \"ProjectPackageManager\",\n+    \"ProjectPackageFile\",\n+    \"ProjectPackageFileManager\",\n ]\n \n \n@@ -28,7 +29,7 @@\n \n \n class ProjectPackage(ObjectDeleteMixin, RESTObject):\n-    pass\n+    _managers = ((\"package_files\", \"ProjectPackageFileManager\"),)\n \n \n class ProjectPackageManager(ListMixin, GetMixin, DeleteMixin, RESTManager):\n@@ -41,3 +42,13 @@\n         \"package_type\",\n         \"package_name\",\n     )\n+\n+\n+class ProjectPackageFile(RESTObject):\n+    pass\n+\n+\n+class ProjectPackageFileManager(ListMixin, RESTManager):\n+    _path = \"/projects/%(project_id)s/packages/%(package_id)s/package_files\"\n+    _obj_cls = ProjectPackageFile\n+    _from_parent_attrs = {\"project_id\": \"project_id\", \"package_id\": \"id\"}\n", "issue": "Cannot list package files\n## Description of the problem, including code/CLI snippet\r\n\r\n[Listing package files](https://docs.gitlab.com/ee/api/packages.html#list-package-files) appears to be unsupported. The API endpoint was introduced in GitLab 11.8.\r\n\r\n## Expected Behavior\r\n\r\nListing package files should be possible.\r\n\r\n## Actual Behavior\r\n\r\nListing package files is not possible.\r\n\r\n## Specifications\r\n\r\n  - python-gitlab version: 2.6.0\r\n  - API version you are using (v3/v4): v4\r\n  - Gitlab server version (or gitlab.com): gitlab.com\r\n\r\n\r\nPR incoming.\n", "before_files": [{"content": "from gitlab.base import RESTManager, RESTObject\nfrom gitlab.mixins import DeleteMixin, GetMixin, ListMixin, ObjectDeleteMixin\n\n\n__all__ = [\n    \"GroupPackage\",\n    \"GroupPackageManager\",\n    \"ProjectPackage\",\n    \"ProjectPackageManager\",\n]\n\n\nclass GroupPackage(RESTObject):\n    pass\n\n\nclass GroupPackageManager(ListMixin, RESTManager):\n    _path = \"/groups/%(group_id)s/packages\"\n    _obj_cls = GroupPackage\n    _from_parent_attrs = {\"group_id\": \"id\"}\n    _list_filters = (\n        \"exclude_subgroups\",\n        \"order_by\",\n        \"sort\",\n        \"package_type\",\n        \"package_name\",\n    )\n\n\nclass ProjectPackage(ObjectDeleteMixin, RESTObject):\n    pass\n\n\nclass ProjectPackageManager(ListMixin, GetMixin, DeleteMixin, RESTManager):\n    _path = \"/projects/%(project_id)s/packages\"\n    _obj_cls = ProjectPackage\n    _from_parent_attrs = {\"project_id\": \"id\"}\n    _list_filters = (\n        \"order_by\",\n        \"sort\",\n        \"package_type\",\n        \"package_name\",\n    )\n", "path": "gitlab/v4/objects/packages.py"}], "after_files": [{"content": "from gitlab.base import RESTManager, RESTObject\nfrom gitlab.mixins import DeleteMixin, GetMixin, ListMixin, ObjectDeleteMixin\n\n__all__ = [\n    \"GroupPackage\",\n    \"GroupPackageManager\",\n    \"ProjectPackage\",\n    \"ProjectPackageManager\",\n    \"ProjectPackageFile\",\n    \"ProjectPackageFileManager\",\n]\n\n\nclass GroupPackage(RESTObject):\n    pass\n\n\nclass GroupPackageManager(ListMixin, RESTManager):\n    _path = \"/groups/%(group_id)s/packages\"\n    _obj_cls = GroupPackage\n    _from_parent_attrs = {\"group_id\": \"id\"}\n    _list_filters = (\n        \"exclude_subgroups\",\n        \"order_by\",\n        \"sort\",\n        \"package_type\",\n        \"package_name\",\n    )\n\n\nclass ProjectPackage(ObjectDeleteMixin, RESTObject):\n    _managers = ((\"package_files\", \"ProjectPackageFileManager\"),)\n\n\nclass ProjectPackageManager(ListMixin, GetMixin, DeleteMixin, RESTManager):\n    _path = \"/projects/%(project_id)s/packages\"\n    _obj_cls = ProjectPackage\n    _from_parent_attrs = {\"project_id\": \"id\"}\n    _list_filters = (\n        \"order_by\",\n        \"sort\",\n        \"package_type\",\n        \"package_name\",\n    )\n\n\nclass ProjectPackageFile(RESTObject):\n    pass\n\n\nclass ProjectPackageFileManager(ListMixin, RESTManager):\n    _path = \"/projects/%(project_id)s/packages/%(package_id)s/package_files\"\n    _obj_cls = ProjectPackageFile\n    _from_parent_attrs = {\"project_id\": \"project_id\", \"package_id\": \"id\"}\n", "path": "gitlab/v4/objects/packages.py"}]}