throw new IllegalArgumentException("Signature field exceeds data buffer size");
        }

        // Use fine-grained locking for better concurrency
        this.signingLock.lock();
        try {
            if (this.closed) {
                throw new IllegalStateException("SigningDigest is closed");
            }

            // zero out signature field
            final int index = offset + SIGNATURE_OFFSET;

            addFieldToSource(sourceMap, "userInfoId", userInfoId);
        }
        return sourceMap;
    }

    protected void addFieldToSource(Map<String, Object> sourceMap, String field, Object value) {
        sourceMap.put(field, value);
    }

    // ===================================================================================
    //                                                                      Basic Override

/**
 * The search form for Group.
 */
public class SearchForm {

    /**
     * Default constructor for SearchForm.
     */
    public SearchForm() {
    }

    /**
     * The ID field for searching groups.
     */
    public String id;

/**
 * The search form for Scheduler.
 */
public class SearchForm {

    /**
     * Default constructor for SearchForm.
     */
    public SearchForm() {
    }

    /**
     * The ID field for searching scheduled jobs.
     */
    public String id;

/**
 * The search form for User.
 */
public class SearchForm {

    /**
     * Default constructor for SearchForm.
     */
    public SearchForm() {
    }

    /**
     * The ID field for searching users.
     */
    public String id;

/**
 * The search form for Request Header.
 */
public class SearchForm {

    /**
     * Default constructor for SearchForm.
     */
    public SearchForm() {
    }

    /**
     * The ID field for searching request headers.
     */
    public String id;

            addFieldToSource(sourceMap, "username", username);
        }
        return sourceMap;
    }

    protected void addFieldToSource(Map<String, Object> sourceMap, String field, Object value) {
        sourceMap.put(field, value);
    }

    // ===================================================================================
    //                                                                      Basic Override

            addFieldToSource(sourceMap, "webConfigId", webConfigId);
        }
        return sourceMap;
    }

    protected void addFieldToSource(Map<String, Object> sourceMap, String field, Object value) {
        sourceMap.put(field, value);
    }

    // ===================================================================================
    //                                                                      Basic Override

    }

    /**
     * Test protected field access
     */
    public void test_protectedFieldAccess() {
        TestTransformer transformer = new TestTransformer();

        // Direct field access (simulating subclass behavior)
        transformer.name = "directFieldAccess";
        assertEquals("directFieldAccess", transformer.getName());

        // Setter should update the field
        transformer.setName("setterAccess");

/**
 * The search form for Stopwords.
 */
public class SearchForm {

    /**
     * Default constructor for SearchForm.
     */
    public SearchForm() {
    }

    /**
     * The dictionary ID field for stopwords dictionary operations.
     */
    @Required
    public String dictId;