How to use the smartmin.users.models.PasswordHistory function in smartmin

def clean_confirm_new_password(self):
        if 'new_password' not in self.cleaned_data:
            return None

        if not self.cleaned_data['confirm_new_password'] and self.cleaned_data['new_password']:
            raise forms.ValidationError(_("Confirm your new password by entering it here"))

        if self.cleaned_data['new_password'] != self.cleaned_data['confirm_new_password']:
            raise forms.ValidationError(_("Mismatch between your new password and confirmation, try again"))

        password = self.cleaned_data['new_password']
        if password and not is_password_complex(password):
            raise forms.ValidationError(_("Passwords must have at least 8 characters, including one uppercase, "
                                          "one lowercase and one number"))

        if password and PasswordHistory.is_password_repeat(self.instance, password):
            raise forms.ValidationError(_("You have used this password before in the past year, "
                                          "please use a new password."))

        return self.cleaned_data['new_password']

def post_save(self, obj):
            obj = super(UserCRUDL.Newpassword, self).post_save(obj)
            PasswordHistory.objects.create(user=obj, password=obj.password)
            return obj

def process_view(self, request, view, *args, **kwargs):
        newpassword_path = reverse('users.user_newpassword', args=[0])
        logout_path = reverse('users.user_logout')

        if (self.password_expire < 0 or not request.user.is_authenticated or view == django.views.static.serve or request.path == newpassword_path or request.path == logout_path):  # noqa
            return

        if PasswordHistory.is_password_expired(request.user):
            return HttpResponseRedirect(reverse('users.user_newpassword', args=['0']))

def is_password_repeat(cls, user, password):
        password_window = getattr(settings, 'USER_PASSWORD_REPEAT_WINDOW', -1)
        if password_window <= 0:
            return False

        # check their current password
        if check_password(password, user.password):
            return True

        # get all the passwords in the past year
        window_ago = timezone.now() - timedelta(days=password_window)
        previous_passwords = PasswordHistory.objects.filter(user=user, set_on__gte=window_ago)
        for previous in previous_passwords:
            if check_password(password, previous.password):
                return True

        return False