How to use the gitlint.utils.sstr function in gitlint

def __str__(self):
        return sstr(self)  # pragma: no cover

def __str__(self):
        return sstr(self)  # pragma: no cover

def __str__(self):
        return sstr(self.__unicode__())  # pragma: no cover

def __unicode__(self):
        format_str = (u"--- Commit Message ----\n%s\n"
                      u"--- Meta info ---------\n"
                      u"Author: %s <%s>\nDate:   %s\n"
                      u"is-merge-commit:  %s\nis-fixup-commit:  %s\n"
                      u"is-squash-commit: %s\nis-revert-commit: %s\n"
                      u"Branches: %s\n"
                      u"Changed Files: %s\n"
                      u"-----------------------")  # pragma: no cover
        date_str = arrow.get(self.date).format(GIT_TIMEFORMAT) if self.date else None
        return format_str % (ustr(self.message), self.author_name, self.author_email, date_str,
                             self.is_merge_commit, self.is_fixup_commit, self.is_squash_commit,
                             self.is_revert_commit, sstr(self.branches), sstr(self.changed_files))  # pragma: no cover

def __str__(self):
        return sstr(self)  # pragma: no cover