// Exceptions
    // ------------------------------------------------------------------------

    public boolean hasExceptions() {
        return exceptions != null && !exceptions.isEmpty();
    }

    public List<Exception> getExceptions() {
        return exceptions == null ? Collections.emptyList() : Collections.unmodifiableList(exceptions);
    }

        assertTrue(endLatch.await(30, TimeUnit.SECONDS), "All threads should complete within timeout");
        executor.shutdown();

        // Then - Verify no exceptions occurred
        if (!exceptions.isEmpty()) {
            fail("Concurrent operations caused exceptions: " + exceptions.get(0));
        }

        assertEquals(threadCount * opsPerThread, successCount.get(), "All operations should succeed");
    }

    /**

        System.out.printf("  Avg tree operation time: %.2f ns%n", avgOpTimeNs);

        // Verify thread safety and performance
        assertTrue(exceptions.isEmpty(), "No exceptions should occur with thread-safe collections: " + exceptions);
        assertEquals(threadCount * operationsPerThread, treeOperations.get());
        assertTrue(avgOpTimeNs < 100000, "Tree operations should be reasonable with CopyOnWriteArrayList");

                                createdComponents.add(component);
                            }
                        }
                    } catch (Exception e) {
                        synchronized (exceptions) {
                            exceptions.add(e);
                        }
                    }
                }
            });
        }

        // Start all threads

 *       will be thrown.
 *   <li>If no exceptions or errors were thrown in the try block, the <i>first</i> exception thrown
 *       by an attempt to close a resource will be thrown.
 *   <li>Any exception caught when attempting to close a resource that is <i>not</i> thrown (because
 *       another exception is already being thrown) is <i>suppressed</i>.
 * </ul>
 *

        assertNotNull(exception);
        assertNull(exception.getCause());
        assertNull(exception.getMessage());
    }

    /**
     * Test constructor with various cause types
     */
    public void test_constructor_withVariousCauseTypes() {
        // With Exception cause
        Exception exceptionCause = new Exception("Exception cause");

                    conn.connect();
                    successCount.incrementAndGet();
                } catch (Exception e) {
                    synchronized (exceptions) {
                        exceptions.add(e);
                    }
                    failureCount.incrementAndGet();
                } finally {
                    doneLatch.countDown();
                }

```

### Exception Handling
```java
import org.codelibs.core.exception.*;

// Runtime exception wrappers eliminate try-catch boilerplate
try {
    // Code that might throw checked exceptions
    return ClassUtil.newInstance(className); // Wraps checked exceptions automatically
} catch (ClassNotFoundRuntimeException e) {
    // Handle the wrapped exception

import org.codelibs.fess.crawler.entity.ExtractData;
import org.codelibs.fess.crawler.exception.CrawlerSystemException;
import org.codelibs.fess.crawler.exception.ExtractException;
import org.dbflute.utflute.core.PlainTestCase;

/**
 * Test class to verify proper resource management in Extractor implementations.
 * This test ensures that resources are properly closed even when exceptions occur.
 */

                    conn.connect();
                    successCount.incrementAndGet();
                } catch (Exception e) {
                    synchronized (exceptions) {
                        exceptions.add(e);
                    }
                    failureCount.incrementAndGet();
                } finally {
                    doneLatch.countDown();
                }