def METHOD_NAME(self, filename):
    self.prefilter_path = filename
    flt = self.get_filter_program(filename)
    if not flt:
        return self._load_file(filename)
    if not self.tmp:
        self.mktemp()
    tmp = os.path.join(self.tmp, os.path.basename(filename))
    flt = FilterProgram(flt, filename, tmp, lambda r: r or self._load_file(tmp))