BZ2Compressor and BZ2Decompressor live in the _bz2 module (#12976)

stdlib/_bz2.pyi

@@ -0,0 +1,18 @@
+from _typeshed import ReadableBuffer
+from typing import final
+
+@final
+class BZ2Compressor:
+    def __init__(self, compresslevel: int = 9) -> None: ...
+    def compress(self, data: ReadableBuffer, /) -> bytes: ...
+    def flush(self) -> bytes: ...
+
+@final
+class BZ2Decompressor:
+    def decompress(self, data: ReadableBuffer, max_length: int = -1) -> bytes: ...
+    @property
+    def eof(self) -> bool: ...
+    @property
+    def needs_input(self) -> bool: ...
+    @property
+    def unused_data(self) -> bytes: ...