@Override
    public int hashCode() {
        if (hashCode == 0) {
            hashCode = Arrays.hashCode(bytes);
        }

        return hashCode;
    }
The hashcode is cached except for the case where it is computed as 0, in which
case we compute the hashcode on every call.

@return the hashcode
clients/src/main/java/org/apache/kafka/common/utils/Bytes.java