@Override
    public ConfigData get(String path, Set<String> keys) {

        if (path != null && !path.isEmpty()) {
            log.error("Path is not supported for EnvVarConfigProvider, invalid value '{}'", path);
            throw new ConfigException("Path is not supported for EnvVarConfigProvider, invalid value '" + path + "'");
        }

        if (keys == null) {
            return new ConfigData(filteredEnvVarMap);
        }

        Map<String, String> filteredData = new HashMap<>(filteredEnvVarMap);
        filteredData.keySet().retainAll(keys);

        return new ConfigData(filteredData);
    }
@param path    path, not used for environment variables
@param keys the keys whose values will be retrieved.
@return the configuration data.
clients/src/main/java/org/apache/kafka/common/config/provider/EnvVarConfigProvider.java