'Clears the dark language preview
Arguments:
request (Request): The incoming Django Request
context dict: The basic context for the Response
Returns:
HttpResponse: View containing the form for setting the preview lang with the status
included in the context'

def _clear_preview_language(self, request, context):

    if (LANGUAGE_SESSION_KEY in request.session):
        del request.session[LANGUAGE_SESSION_KEY]
    user_pref = ''
    auth_user = request.user
    if auth_user:
        delete_user_preference(auth_user, DARK_LANGUAGE_KEY)
        user_pref = get_user_preference(auth_user, LANGUAGE_KEY)
        if user_pref:
            request.session[LANGUAGE_SESSION_KEY] = user_pref
    if (user_pref is None):
        message = _('Language    reset    to    the    default    language    code')
    else:
        message = _("Language    reset    to    user's    preference:    {preview_language_code}").format(preview_language_code=user_pref)
    context.update({'form_submit_message': message})
    context.update({'success': True})
    return render_to_response(self.template_name, context)
