'Save a copy of the specified format as ORIGINAL_FORMAT, overwriting any existing ORIGINAL_FORMAT.'

@api
def save_original_format(self, book_id, fmt):

    fmt = fmt.upper()
    if (u'ORIGINAL' in fmt):
        raise ValueError(u'Cannot    save    original    of    an    original    fmt')
    fmtfile = self.format(book_id, fmt, as_file=True)
    if (fmtfile is None):
        return False
    with fmtfile:
        nfmt = (u'ORIGINAL_' + fmt)
        return self.add_format(book_id, nfmt, fmtfile, run_hooks=False)
