def close(self) -> None:
        """
        To act as a file.
        """
        if self.underlying_stream:
            if self.using_stdout:
                sys.stdout = self.underlying_stream
            else:
                sys.stderr = self.underlying_stream
            self.underlying_stream = None
        if self.file:
            # Do NOT close the file; we don't own it.
            self.file = None
            log.debug("Finished copying {} to {}",
                      self.output_description, self.filename)