def decode(cls, data, bytes_to_read=None):
        """Compressed messages should pass in bytes_to_read (via message size)
        otherwise, we decode from data as Int32
        """
        if isinstance(data, bytes):
            data = io.BytesIO(data)
        if bytes_to_read is None:
            bytes_to_read = Int32.decode(data)

        # if FetchRequest max_bytes is smaller than the available message set
        # the server returns partial data for the final message
        # So create an internal buffer to avoid over-reading
        raw = io.BytesIO(data.read(bytes_to_read))

        items = []
        while bytes_to_read:
            try:
                offset = Int64.decode(raw)
                msg_bytes = Bytes.decode(raw)
                bytes_to_read -= 8 + 4 + len(msg_bytes)
                items.append((offset, len(msg_bytes), Message.decode(msg_bytes)))
            except ValueError:
                # PartialMessage to signal that max_bytes may be too small
                items.append((None, None, PartialMessage()))
                break
        return items
Compressed messages should pass in bytes_to_read (via message size)
        otherwise, we decode from data as Int32
        
kafka/protocol/message.py