Hacky support in stub for both the old and new APIs

Only one of these works at runtime, however.

Author: JukkaL

mypy/typeshed/stubs/librt/librt/internal.pyi

@@ -1,21 +1,27 @@
 from mypy_extensions import u8
 
+# TODO: Remove Buffer -- right now we have hacky support for BOTH the old and new APIs
+
+class Buffer:
+    def __init__(self, source: bytes = ...) -> None: ...
+    def getvalue(self) -> bytes: ...
+
 class ReadBuffer:
     def __init__(self, source: bytes) -> None: ...
 
 class WriteBuffer:
     def getvalue(self) -> bytes: ...
 
-def write_bool(data: WriteBuffer, value: bool) -> None: ...
-def read_bool(data: ReadBuffer) -> bool: ...
-def write_str(data: WriteBuffer, value: str) -> None: ...
-def read_str(data: ReadBuffer) -> str: ...
-def write_bytes(data: WriteBuffer, value: bytes) -> None: ...
-def read_bytes(data: ReadBuffer) -> bytes: ...
-def write_float(data: WriteBuffer, value: float) -> None: ...
-def read_float(data: ReadBuffer) -> float: ...
-def write_int(data: WriteBuffer, value: int) -> None: ...
-def read_int(data: ReadBuffer) -> int: ...
-def write_tag(data: WriteBuffer, value: u8) -> None: ...
-def read_tag(data: ReadBuffer) -> u8: ...
+def write_bool(data: WriteBuffer | Buffer, value: bool) -> None: ...
+def read_bool(data: ReadBuffer | Buffer) -> bool: ...
+def write_str(data: WriteBuffer | Buffer, value: str) -> None: ...
+def read_str(data: ReadBuffer | Buffer) -> str: ...
+def write_bytes(data: WriteBuffer | Buffer, value: bytes) -> None: ...
+def read_bytes(data: ReadBuffer | Buffer) -> bytes: ...
+def write_float(data: WriteBuffer | Buffer, value: float) -> None: ...
+def read_float(data: ReadBuffer | Buffer) -> float: ...
+def write_int(data: WriteBuffer | Buffer, value: int) -> None: ...
+def read_int(data: ReadBuffer | Buffer) -> int: ...
+def write_tag(data: WriteBuffer | Buffer, value: u8) -> None: ...
+def read_tag(data: ReadBuffer | Buffer) -> u8: ...
 def cache_version() -> u8: ...