def reload_napps(self, napps=None):
        """Reload a specific NApp or all Napps.

        Args:
            napp (list): NApp list to be reload.
        Raises:
            requests.HTTPError: When there's a server error.

        """
        if napps is None:
            napps = []
            api = self._config.get('kytos', 'api')
            endpoint = os.path.join(api, 'api', 'kytos', 'core', 'reload',
                                    'all')
            response = self.make_request(endpoint)

        for napp in napps:
            api = self._config.get('kytos', 'api')
            endpoint = os.path.join(api, 'api', 'kytos', 'core', 'reload',
                                    napp[0], napp[1])
            response = self.make_request(endpoint)

        if response.status_code != 200:
            raise KytosException('Error reloading the napp: Module not founded'
                                 ' or could not be imported')

        return response.content