assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.add(e3()));
          iterator.next();
        });
  }

  /**
   * Returns the {@link Method} instance for {@link #testAdd_nullSupported()} so that tests of
   * {@link java.util.Collections#checkedCollection(java.util.Collection, Class)} can suppress it

This would be typical after a user initiates a force refresh by a pull to refresh type action.

```java
    val urlIterator = cache.urls()
    while (urlIterator.hasNext()) {
      if (urlIterator.next().startsWith("https://www.google.com/")) {
        urlIterator.remove()
      }
    }
```

### Troubleshooting

1. Valid cacheable responses are not being cached

  interface Callback {
    fun onEvent(
      id: String?,
      type: String?,
      data: String,
    )

    fun onRetryChange(timeMs: Long)
  }

  /**
   * Process the next event. This will result in a single call to [Callback.onEvent] *unless* the
   * data section was empty. Any number of calls to [Callback.onRetryChange] may occur while
   * processing an event.
   *

            }
        }
    }

    /**
     * Polls the next URL queue entry for the specified session.
     * This method manages local caches and fetches from OpenSearch when needed.
     *
     * @param sessionId The session ID.
     * @return The next URL queue entry, or null if none available.
     */
    @Override

   * If an {@code Error} is thrown, the error will propagate and execution will stop until the next
   * time a task is submitted.
   *
   * <p>When an {@code Error} is thrown by an executed task, previously submitted tasks may never
   * run. An attempt will be made to restart execution on the next call to {@code execute}. If the
   * {@code delegate} has begun to reject execution, the previously submitted tasks may never run,

            Set<RequestData> childUrls = e.getChildUrlList();
            assertNotNull(childUrls);
            assertEquals(1, childUrls.size());

            RequestData requestData = childUrls.iterator().next();
            assertEquals("https://example.com/page1", requestData.getUrl());
        }
    }

    public void test_processMultipleSitemaps() {
        // Setup

     * @throws IOException if an I/O error occurs
     */
    protected abstract void makeKey(Request request) throws IOException;

    /**
     * Reads and returns the key of the next message without consuming it.
     *
     * @return the request key of the next message
     * @throws IOException if an I/O error occurs
     */
    protected abstract Request peekKey() throws IOException;

    /**

import org.codelibs.core.lang.StringUtil;
import org.codelibs.core.misc.Tuple3;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.lastaflute.web.response.next.HtmlNext;
import org.lastaflute.web.util.LaRequestUtil;

/**
 * Helper class for managing virtual host configurations and routing.
 * This class provides functionality to handle virtual host-based routing

   * its runtime check.
   *
   * <p>An example use case for this method is in implementing an {@code Iterator<T>} whose {@code
   * next} field is lazily initialized. The type of that field would be {@code @Nullable T}, and the
   * code would be responsible for populating a "real" {@code T} (which might still be the value

   * its runtime check.
   *
   * <p>An example use case for this method is in implementing an {@code Iterator<T>} whose {@code
   * next} field is lazily initialized. The type of that field would be {@code @Nullable T}, and the
   * code would be responsible for populating a "real" {@code T} (which might still be the value