assertFalse(thumbnailGenerator.generate(thumbnailId, null));
    }

    public void test_generate_withInvalidOutputPath() throws IOException {
        // Test generation with non-writable output file
        File readOnlyDir = Files.createTempDirectory(tempDir, "readonly").toFile();
        readOnlyDir.setWritable(false);
        File invalidOutputFile = new File(readOnlyDir, "thumbnail.png");

        if (field != null && ModifierUtil.isPublic(field)) {
            readable = true;
            writable = true;
        }
    }

    @Override
    public boolean isReadable() {
        return readable;
    }

    @Override
    public boolean isWritable() {
        return writable;
    }

    @Override
    public <T> T getValue(final Object target) {

        assertEquals(0, exception.getSuppressed().length);
    }

    public void test_constructor_withWritableStackTrace() {
        // Test protected constructor with writable stack trace
        String message = "Test with writable stack trace";
        TestFessSystemException exception = new TestFessSystemException(message, true, true);

        assertEquals(message, exception.getMessage());

     *
     * @param message the detail message describing the exception
     * @param enableSuppression whether suppression is enabled or disabled
     * @param writableStackTrace whether the stack trace should be writable
     */
    protected FessSystemException(final String message, final boolean enableSuppression, final boolean writableStackTrace) {
        super(message, null, enableSuppression, writableStackTrace);
    }

import org.dbflute.Entity;
import org.dbflute.bhv.AbstractBehaviorWritable;
import org.dbflute.bhv.readable.EntityRowHandler;
import org.dbflute.bhv.writable.DeleteOption;
import org.dbflute.bhv.writable.InsertOption;
import org.dbflute.bhv.writable.UpdateOption;
import org.dbflute.cbean.ConditionBean;
import org.dbflute.cbean.coption.CursorSelectOption;
import org.dbflute.cbean.result.ListResultBean;

import org.dbflute.Entity;
import org.dbflute.bhv.AbstractBehaviorWritable;
import org.dbflute.bhv.readable.EntityRowHandler;
import org.dbflute.bhv.writable.DeleteOption;
import org.dbflute.bhv.writable.InsertOption;
import org.dbflute.bhv.writable.UpdateOption;
import org.dbflute.cbean.ConditionBean;
import org.dbflute.cbean.coption.CursorSelectOption;
import org.dbflute.cbean.result.ListResultBean;

        assertTrue(exception instanceof Exception);
        assertTrue(exception instanceof Throwable);
    }

    public void test_stackTraceForMessageOnlyConstructor() {
        // Test that stack trace is not writable when using message-only constructor
        ThumbnailGenerationException exception = new ThumbnailGenerationException("Test message");

    }
  }

  public static <K, V> ImmutableBiMap<K, V> copyOf(Map<? extends K, ? extends V> map) {
    if (map instanceof ImmutableBiMap) {
      @SuppressWarnings("unchecked") // safe since map is not writable
      ImmutableBiMap<K, V> bimap = (ImmutableBiMap<K, V>) map;
      return bimap;
    }

    if (map.isEmpty()) {
      return of();
    }

import org.dbflute.Entity;
import org.dbflute.bhv.AbstractBehaviorWritable;
import org.dbflute.bhv.readable.EntityRowHandler;
import org.dbflute.bhv.writable.DeleteOption;
import org.dbflute.bhv.writable.InsertOption;
import org.dbflute.bhv.writable.UpdateOption;
import org.dbflute.cbean.ConditionBean;
import org.dbflute.cbean.coption.CursorSelectOption;
import org.dbflute.cbean.result.ListResultBean;

  public static <K, V> ImmutableMap<K, V> copyOf(Map<? extends K, ? extends V> map) {
    if ((map instanceof ImmutableMap) && !(map instanceof ImmutableSortedMap)) {
      @SuppressWarnings("unchecked") // safe since map is not writable
      ImmutableMap<K, V> kvMap = (ImmutableMap<K, V>) map;
      return kvMap;
    } else if (map instanceof EnumMap) {
      EnumMap<?, ?> enumMap = (EnumMap<?, ?>) map;