Download the contents of this blob into a named file.

        If :attr:`user_project` is set on the bucket, bills the API request
        to that project.

        :type filename: str
        :param filename: A filename to be passed to ``open``.

        :type client: :class:`~google.cloud.storage.client.Client` or
                      ``NoneType``
        :param client: Optional. The client to use.  If not passed, falls back
                       to the ``client`` stored on the blob's bucket.

        :type start: int
        :param start: Optional, the first byte in a range to be downloaded.

        :type end: int
        :param end: Optional, The last byte in a range to be downloaded.

        :raises: :class:`google.cloud.exceptions.NotFound`

def download_to_filename(self, filename, client=None, start=None, end=None):
        """Download the contents of this blob into a named file.

        If :attr:`user_project` is set on the bucket, bills the API request
        to that project.

        :type filename: str
        :param filename: A filename to be passed to ``open``.

        :type client: :class:`~google.cloud.storage.client.Client` or
                      ``NoneType``
        :param client: Optional. The client to use.  If not passed, falls back
                       to the ``client`` stored on the blob's bucket.

        :type start: int
        :param start: Optional, the first byte in a range to be downloaded.

        :type end: int
        :param end: Optional, The last byte in a range to be downloaded.

        :raises: :class:`google.cloud.exceptions.NotFound`
        """
        try:
            with open(filename, "wb") as file_obj:
                self.download_to_file(file_obj, client=client, start=start, end=end)
        except resumable_media.DataCorruption:
            # Delete the corrupt downloaded file.
            os.remove(filename)
            raise

        updated = self.updated
        if updated is not None:
            mtime = time.mktime(updated.timetuple())
            os.utime(file_obj.name, (mtime, mtime))