prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <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.
  
  </issue>
  <code>
  [start of gitlab/v4/objects/packages.py]
  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 of gitlab/v4/objects/packages.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
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"}]}