class StepFileIO(io.FileIO):
    def __init__(self, *args, **kwargs):
        super(StepFileIO, self).__init__(*args, **kwargs)

    def fileno(self) -> int:
        return -1

    def seek(self, __offset: int, __whence: int = ...) -> int:
        return super().seek(__offset, __whence)

    def __sizeof__(self):
        return super().__sizeof__() - 32

    def read(self, __size: int = ...) -> bytes:
        self.seek(self.tell() + 32, 0)
        __size -= 32
        return super().read(__size)