default String afToString() {
        StringBuilder sb = new StringBuilder();
        sb.append("{ value:'").append(getValue()).append("', confidence:'").append(getConfidence()).append("', ");

        String defaultValue = getDefaultValue();
        if (defaultValue == null) {
            sb.append("default:null, ");
        } else {
            sb.append("default:'").append(getDefaultValue()).append("', ");
        }
        sb.append("isDefault:").append(isDefaultValue()).append(" }");
        return sb.toString();
    }
@return The default value for this field in case we do not know what this is.
analyzer/src/main/java/nl/basjes/parse/useragent/AgentField.java