*       C}, instance methods are skipped for nulls test.
   *   <li>Nulls test is not performed on method return values unless the method is a visible static
   *       factory method whose return type is {@code C} or {@code C}'s subtype.
   * </ul>
   *
   * <p>In all cases, if {@code C} needs custom logic for testing nulls, you can add an explicit

        return loader.load(key);
      }

      @Override
      public Map<K, V> loadAll(Iterable<? extends K> keys) throws Exception {
        Map<K, V> result = new HashMap<>(); // allow nulls
        for (K key : keys) {
          result.put(key, load(key));
        }
        return result;
      }
    };
  }

   *       C}, instance methods are skipped for nulls test.
   *   <li>Nulls test is not performed on method return values unless the method is a visible static
   *       factory method whose return type is {@code C} or {@code C}'s subtype.
   * </ul>
   *
   * <p>In all cases, if {@code C} needs custom logic for testing nulls, you can add an explicit

import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * An ordering that treats all references as equals, even nulls.
 *
 * @author Emily Soldal
 */
@GwtCompatible
final class AllEqualOrdering extends Ordering<@Nullable Object> implements Serializable {
  static final AllEqualOrdering INSTANCE = new AllEqualOrdering();

import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * An ordering that treats all references as equals, even nulls.
 *
 * @author Emily Soldal
 */
@GwtCompatible
final class AllEqualOrdering extends Ordering<@Nullable Object> implements Serializable {
  static final AllEqualOrdering INSTANCE = new AllEqualOrdering();

    }

    /**
     * Test getAnchorSet with null input
     */
    @Test
    public void test_getAnchorSet_withNull() {
        FessCrawlerThread crawlerThread = new FessCrawlerThread();

        Set<RequestData> result = crawlerThread.getAnchorSet(null);
        assertNull(result, "getAnchorSet should return null for null input");
    }

    /**
     * Test getAnchorSet with single string

       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's
       * worth noting that we promise not to put nulls into the array in the first `size` elements.
       * We uphold that promise here because our callers promise that `elements` will not contain
       * nulls in its first `n` elements.
       */
      System.arraycopy(elements, 0, contents, size, n);
      size += n;

   * array of the erased type.
   */
  T create(Object... elements);

  /**
   * Helper method to create an array of the appropriate type used by this generator. The returned
   * array will contain only nulls.
   */
  E[] createArray(int length);

  /**
   * Returns the iteration ordering of elements, given the order in which they were added to the

  /**
   * Visits the given types. Null types are ignored. This allows subclasses to call {@code
   * visit(parameterizedType.getOwnerType())} safely without having to check nulls.
   */
  public final void visit(@Nullable Type... types) {
    for (Type type : types) {
      if (type == null || !visited.add(type)) {
        // null owner type, or already visited;
        continue;
      }

  @Override
  public boolean contains(@Nullable Object target) {
    @Nullable Object[] table = this.table;
    if (target == null || table.length == 0) {
      return false;
    }
    for (int i = smearedHash(target); ; i++) {
      i &= mask;
      Object candidate = table[i];
      if (candidate == null) {
        return false;
      } else if (candidate.equals(target)) {
        return true;
      }
    }
  }