public void addOptionalField(String optionalField) {
        if (optionalField == null) {
            return;
        } else if (this.optionalFields == null) {
            this.optionalFields = new ArrayList<String >();
        }
        this.optionalFields.add(optionalField);
    }
Add a field to the list of optional fields that are included in the inventory results.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/inventory/InventoryConfiguration.java