* collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_nullCollectionReferenceEmptySubject() {
    try {
      collection.retainAll(null);

     * be an unchanging snapshot of the count at the time the entry was retrieved, or a live view of
     * the current count of the element in the multiset, depending on the implementation. Note that
     * in the former case, this method can never return zero, while in the latter, it will return
     * zero if all occurrences of the element were since removed from the multiset.
     *
     * @return the count of the element; never negative

     * be an unchanging snapshot of the count at the time the entry was retrieved, or a live view of
     * the current count of the element in the multiset, depending on the implementation. Note that
     * in the former case, this method can never return zero, while in the latter, it will return
     * zero if all occurrences of the element were since removed from the multiset.
     *
     * @return the count of the element; never negative

     * For example, if you specify an underscore as the delimiter for JavaBeans and a period as the delimiter for {@link Map},
     * the property names for the source and destination will be as follows:
     * </p>
     * <table border="1">
     * <caption>Copied JavaBeans Properties</caption>
     * <tr>
     * <th>JavaBeans Property Name</th>
     * <th>{@literal Map} Property Name</th>
     * </tr>
     * <tr>

labels.advance_search_must_queries=mit allen Wörtern
labels.advance_search_phrase_query=mit der exakten Wortgruppe
labels.advance_search_should_queries=mit mindestens einem der Wörter
labels.advance_search_not_queries=ohne die Wörter
labels.advance_search_filetype=Dateityp
labels.advance_search_filetype_default=Beliebiges Format
labels.advance_search_filetype_html=HTML
labels.advance_search_filetype_pdf=PDF

                        <div
                                class="card card-outline <c:if test="${crudMode == 1 || crudMode == 2}">card-success</c:if>">
                            <div class="card-header with-border">
                                <jsp:include page="/WEB-INF/view/common/admin/crud/header.jsp"></jsp:include>
                            </div>
                            <div class="card-body">

  /**
   * Returns the {@link Executor} that will be used to run this service. Subclasses may override
   * this method to use a custom {@link Executor}, which may configure its worker thread with a
   * specific name, thread group or priority. The returned executor's {@link
   * Executor#execute(Runnable) execute()} method is called when this service is started, and should
   * return promptly.
   *

    text-decoration: none;
    color: #000000;
    background-color: #d0d0d0;
    border-top-color: #ffffff;
    border-bottom-color: #707070;
    border-right-color: #707070;
    border-left-color: #ffffff;
    border-style: solid solid;
    border-top-width: 1px;
    border-bottom-width: 2px;
    border-right-width: 2px;
    border-left-width: 1px
}
a:visited {
    color: #333897
}
a.sort:hover {

int maxDepth = -1               // Max depth (-1 = unlimited)
long maxAccessCount = 0         // Max URLs (0 = unlimited)
```

### CrawlerThread (`CrawlerThread.java`)

Worker thread for crawling.

**Flow**: Poll URL → Validate → Get client → Delay → Check last-modified → Execute → Process → Extract children → Queue children → Delay

### CrawlerClientFactory

      }
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**
   * Returns every possible list that can be formed by choosing one element from each of the given
   * lists in order; the "n-ary <a href="http://en.wikipedia.org/wiki/Cartesian_product">Cartesian
   * product</a>" of the lists. For example:
   *
   * {@snippet :