def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def save(self, *args, **kwargs):
        # Get all other primary domains with the same tenant
        domain_list = self.__class__.objects.filter(tenant=self.tenant, is_primary=True).exclude(pk=self.pk)
        # If we have no primary domain yet, set as primary domain by default
        self.is_primary = self.is_primary or (not domain_list.exists())
        if self.is_primary:
            # Remove primary status of existing domains for tenant
            domain_list.update(is_primary=False)
        super().save(*args, **kwargs)