Improve typing for BS4 element.Tag's get and get_attribute_list. (#12840)

Author: Kevin Mustelier

stubs/beautifulsoup4/bs4/element.pyi

@@ -27,6 +27,7 @@ class ContentMetaAttributeValue(AttributeValueWithCharsetSubstitution):
     def __new__(cls, original_value): ...
     def encode(self, encoding: str) -> str: ...  # type: ignore[override]  # incompatible with str
 
+_T = TypeVar("_T")
 _PageElementT = TypeVar("_PageElementT", bound=PageElement)
 _SimpleStrainable: TypeAlias = str | bool | None | bytes | Pattern[str] | Callable[[str], bool] | Callable[[Tag], bool]
 _Strainable: TypeAlias = _SimpleStrainable | Iterable[_SimpleStrainable]
@@ -276,8 +277,16 @@ class Tag(PageElement):
     def clear(self, decompose: bool = False) -> None: ...
     def smooth(self) -> None: ...
     def index(self, element: PageElement) -> int: ...
-    def get(self, key: str, default: str | list[str] | None = None) -> str | list[str] | None: ...
-    def get_attribute_list(self, key: str, default: str | list[str] | None = None) -> list[str]: ...
+    @overload
+    def get(self, key: str, default: None = None) -> str | list[str] | None: ...
+    @overload
+    def get(self, key: str, default: _T) -> str | list[str] | _T: ...
+    @overload
+    def get_attribute_list(self, key: str, default: None = None) -> list[str | None]: ...
+    @overload
+    def get_attribute_list(self, key: str, default: list[_T]) -> list[str | _T]: ...
+    @overload
+    def get_attribute_list(self, key: str, default: _T) -> list[str | _T]: ...
     def has_attr(self, key: str) -> bool: ...
     def __hash__(self) -> int: ...
     def __getitem__(self, key: str) -> str | list[str]: ...