public Map<String, String> originalsStrings() {
        Map<String, String> copy = new RecordingMap<>();
        for (Map.Entry<String, ?> entry : originals.entrySet()) {
            if (!(entry.getValue() instanceof String))
                throw new ClassCastException("Non-string value found in original settings for key " + entry.getKey() +
                        ": " + (entry.getValue() == null ? null : entry.getValue().getClass().getName()));
            copy.put(entry.getKey(), (String) entry.getValue());
        }
        return copy;
    }
Get all the original settings, ensuring that all values are of type String.

@return the original settings
@throws ClassCastException if any of the values are not strings
clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java