public static Map<String, String> propsToStringMap(Properties props) {
        Map<String, String> result = new HashMap<>();
        for (Map.Entry<Object, Object> entry : props.entrySet())
            result.put(entry.getKey().toString(), entry.getValue().toString());
        return result;
    }
Converts a Properties object to a Map<String, String>, calling {@link #toString} to ensure all keys and values
are Strings.
clients/src/main/java/org/apache/kafka/common/utils/Utils.java