return getEnvMap().entrySet().stream().filter(e -> {
            final String key = e.getKey();
            if (StringUtil.isBlank(key)) {
                return false;
            }
            return pattern.matcher(key).matches();
        }).collect(Collectors.toMap(Entry<String, String>::getKey, Entry<String, String>::getValue));
    }

    protected Map<String, String> getEnvMap() {
        return System.getenv();
    }