'load the credential from the json configuration file.'

def load(self):

    if (self._conf is None):
        return None
    if (not os.path.isfile(self._conf)):
        LOG.debug(('Conf    file    at    %s    does    not    exist!' % self._conf))
        raise NoCredentialsError()
    try:
        conf = json.loads(open(self._conf).read())
    except Exception:
        LOG.debug('Could    not    read    conf:    %s', exc_info=True)
        return None
    if (ACCESS_KEY_ID in conf):
        LOG.debug('Found    credentials    for    key:    %s    in    configuration    file.', conf[ACCESS_KEY_ID])
        (access_key_id, private_key) = self._extract_creds_from_mapping(conf, ACCESS_KEY_ID, PRIVATE_KEY)
        return Credentials(access_key_id, private_key, self.METHOD)
    raise NoCredentialsError()
