diff --git a/github/Milestone.py b/github/Milestone.py
index 1a0882eb..dc9e4be5 100644
--- a/github/Milestone.py
+++ b/github/Milestone.py
@@ -27,193 +27,148 @@
 # along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
 #                                                                              #
 ################################################################################
+from __future__ import annotations
 
-from datetime import date
-from typing import Any, Dict
+from datetime import date, datetime
+from typing import Any
 
 import github.GithubObject
 import github.Label
 import github.NamedUser
 import github.PaginatedList
+from github.GithubObject import Attribute, CompletableGithubObject, NotSet, Opt, is_defined
+from github.PaginatedList import PaginatedList
 
 
-class Milestone(github.GithubObject.CompletableGithubObject):
+class Milestone(CompletableGithubObject):
     """
     This class represents Milestones. The reference can be found here https://docs.github.com/en/rest/reference/issues#milestones
     """
 
-    def __repr__(self):
+    def _initAttributes(self) -> None:
+        self._closed_issues: Attribute[int] = NotSet
+        self._created_at: Attribute[datetime] = NotSet
+        self._creator: Attribute[github.NamedUser.NamedUser] = NotSet
+        self._description: Attribute[str] = NotSet
+        self._due_on: Attribute[datetime] = NotSet
+        self._id: Attribute[int] = NotSet
+        self._labels_url: Attribute[str] = NotSet
+        self._number: Attribute[int] = NotSet
+        self._open_issues: Attribute[int] = NotSet
+        self._state: Attribute[str] = NotSet
+        self._title: Attribute[str] = NotSet
+        self._updated_at: Attribute[datetime] = NotSet
+        self._url: Attribute[str] = NotSet
+
+    def __repr__(self) -> str:
         return self.get__repr__({"number": self._number.value, "title": self._title.value})
 
     @property
-    def closed_issues(self):
-        """
-        :type: integer
-        """
+    def closed_issues(self) -> int:
         self._completeIfNotSet(self._closed_issues)
         return self._closed_issues.value
 
     @property
-    def created_at(self):
-        """
-        :type: datetime
-        """
+    def created_at(self) -> datetime:
         self._completeIfNotSet(self._created_at)
         return self._created_at.value
 
     @property
-    def creator(self):
-        """
-        :type: :class:`github.NamedUser.NamedUser`
-        """
+    def creator(self) -> github.NamedUser.NamedUser:
         self._completeIfNotSet(self._creator)
         return self._creator.value
 
     @property
-    def description(self):
-        """
-        :type: string
-        """
+    def description(self) -> str:
         self._completeIfNotSet(self._description)
         return self._description.value
 
     @property
-    def due_on(self):
-        """
-        :type: datetime
-        """
+    def due_on(self) -> datetime | None:
         self._completeIfNotSet(self._due_on)
         return self._due_on.value
 
     @property
-    def id(self):
-        """
-        :type: integer
-        """
+    def id(self) -> int:
         self._completeIfNotSet(self._id)
         return self._id.value
 
     @property
-    def labels_url(self):
-        """
-        :type: string
-        """
+    def labels_url(self) -> str:
         self._completeIfNotSet(self._labels_url)
         return self._labels_url.value
 
     @property
-    def number(self):
-        """
-        :type: integer
-        """
+    def number(self) -> int:
         self._completeIfNotSet(self._number)
         return self._number.value
 
     @property
-    def open_issues(self):
-        """
-        :type: integer
-        """
+    def open_issues(self) -> int:
         self._completeIfNotSet(self._open_issues)
         return self._open_issues.value
 
     @property
-    def state(self):
-        """
-        :type: string
-        """
+    def state(self) -> str:
         self._completeIfNotSet(self._state)
         return self._state.value
 
     @property
-    def title(self):
-        """
-        :type: string
-        """
+    def title(self) -> str:
         self._completeIfNotSet(self._title)
         return self._title.value
 
     @property
-    def updated_at(self):
-        """
-        :type: datetime
-        """
+    def updated_at(self) -> datetime:
         self._completeIfNotSet(self._updated_at)
         return self._updated_at.value
 
     @property
-    def url(self):
-        """
-        :type: string
-        """
+    def url(self) -> str:
         self._completeIfNotSet(self._url)
         return self._url.value
 
-    def delete(self):
+    def delete(self) -> None:
         """
         :calls: `DELETE /repos/{owner}/{repo}/milestones/{number} <https://docs.github.com/en/rest/reference/issues#milestones>`_
-        :rtype: None
         """
         headers, data = self._requester.requestJsonAndCheck("DELETE", self.url)
 
     def edit(
-        self,
-        title,
-        state=github.GithubObject.NotSet,
-        description=github.GithubObject.NotSet,
-        due_on=github.GithubObject.NotSet,
-    ):
+        self, title: str, state: Opt[str] = NotSet, description: Opt[str] = NotSet, due_on: Opt[date] = NotSet
+    ) -> None:
         """
         :calls: `PATCH /repos/{owner}/{repo}/milestones/{number} <https://docs.github.com/en/rest/reference/issues#milestones>`_
-        :param title: string
-        :param state: string
-        :param description: string
-        :param due_on: date
-        :rtype: None
         """
         assert isinstance(title, str), title
-        assert state is github.GithubObject.NotSet or isinstance(state, str), state
-        assert description is github.GithubObject.NotSet or isinstance(description, str), description
-        assert due_on is github.GithubObject.NotSet or isinstance(due_on, date), due_on
-        post_parameters = {
-            "title": title,
-        }
-        if state is not github.GithubObject.NotSet:
-            post_parameters["state"] = state
-        if description is not github.GithubObject.NotSet:
-            post_parameters["description"] = description
-        if due_on is not github.GithubObject.NotSet:
+        assert state is NotSet or isinstance(state, str), state
+        assert description is NotSet or isinstance(description, str), description
+        assert due_on is NotSet or isinstance(due_on, date), due_on
+        post_parameters = NotSet.remove_unset_items(
+            {
+                "title": title,
+                "state": state,
+                "description": description,
+            }
+        )
+
+        if is_defined(due_on):
             post_parameters["due_on"] = due_on.strftime("%Y-%m-%d")
+
         headers, data = self._requester.requestJsonAndCheck("PATCH", self.url, input=post_parameters)
         self._useAttributes(data)
 
-    def get_labels(self):
+    def get_labels(self) -> PaginatedList[github.Label.Label]:
         """
         :calls: `GET /repos/{owner}/{repo}/milestones/{number}/labels <https://docs.github.com/en/rest/reference/issues#labels>`_
-        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Label.Label`
         """
-        return github.PaginatedList.PaginatedList(github.Label.Label, self._requester, f"{self.url}/labels", None)
+        return PaginatedList(github.Label.Label, self._requester, f"{self.url}/labels", None)
 
     @property
-    def _identity(self):
+    def _identity(self) -> int:
         return self.number
 
-    def _initAttributes(self) -> None:
-        self._closed_issues = github.GithubObject.NotSet
-        self._created_at = github.GithubObject.NotSet
-        self._creator = github.GithubObject.NotSet
-        self._description = github.GithubObject.NotSet
-        self._due_on = github.GithubObject.NotSet
-        self._id = github.GithubObject.NotSet
-        self._labels_url = github.GithubObject.NotSet
-        self._number = github.GithubObject.NotSet
-        self._open_issues = github.GithubObject.NotSet
-        self._state = github.GithubObject.NotSet
-        self._title = github.GithubObject.NotSet
-        self._updated_at = github.GithubObject.NotSet
-        self._url = github.GithubObject.NotSet
-
-    def _useAttributes(self, attributes: Dict[str, Any]) -> None:
+    def _useAttributes(self, attributes: dict[str, Any]) -> None:
         if "closed_issues" in attributes:  # pragma no branch
             self._closed_issues = self._makeIntAttribute(attributes["closed_issues"])
         if "created_at" in attributes:  # pragma no branch
diff --git a/github/Milestone.pyi b/github/Milestone.pyi
deleted file mode 100644
index b0f41c8a..00000000
--- a/github/Milestone.pyi
+++ /dev/null
@@ -1,49 +0,0 @@
-from datetime import date, datetime
-from typing import Any, Dict, Optional, Union
-
-from github.GithubObject import CompletableGithubObject, _NotSetType
-from github.Label import Label
-from github.NamedUser import NamedUser
-from github.PaginatedList import PaginatedList
-
-class Milestone(CompletableGithubObject):
-    def __repr__(self) -> str: ...
-    @property
-    def _identity(self) -> int: ...
-    def _initAttributes(self) -> None: ...
-    def _useAttributes(self, attributes: Dict[str, Any]) -> None: ...
-    @property
-    def closed_issues(self) -> int: ...
-    @property
-    def created_at(self) -> datetime: ...
-    @property
-    def creator(self) -> NamedUser: ...
-    def delete(self) -> None: ...
-    @property
-    def description(self) -> str: ...
-    @property
-    def due_on(self) -> Optional[datetime]: ...
-    def edit(
-        self,
-        title: str,
-        state: Union[_NotSetType, str] = ...,
-        description: Union[_NotSetType, str] = ...,
-        due_on: Union[date, _NotSetType] = ...,
-    ) -> None: ...
-    def get_labels(self) -> PaginatedList[Label]: ...
-    @property
-    def id(self) -> int: ...
-    @property
-    def labels_url(self) -> str: ...
-    @property
-    def number(self) -> int: ...
-    @property
-    def open_issues(self) -> int: ...
-    @property
-    def state(self) -> str: ...
-    @property
-    def title(self) -> str: ...
-    @property
-    def updated_at(self) -> datetime: ...
-    @property
-    def url(self) -> str: ...