* @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.
   */
  @SuppressWarnings("unchecked")
  public static <T> Collector<T, ?, Optional<T>> toOptional() {
    return (Collector) TO_OPTIONAL;
  }

  private static final Object NULL_PLACEHOLDER = new Object();

        // `key` was in the cache, so it's a K.
        // (Or it's a weird case like a LinkedList in a Cache<ArrayList, ...>, but *shrug*.)
        @SuppressWarnings({"unchecked", "nullness"})
        K castKey = (K) key;
        @SuppressWarnings({"unchecked", "nullness"}) // similar to the above
        V castValue = (V) value;

        alertListenerIfPresent(castKey, castValue, RemovalCause.EXPLICIT);
        remove(key);

        assertEquals(1, response2.getNum());
        assertEquals(1, response2.getTotal());
    }

    @Test
    @SuppressWarnings("unchecked")
    public void test_indexFromDocument() throws Exception {
        SuggestSettings settings = suggester.settings();
        String field = settings.array().get(SuggestSettings.DefaultKeys.SUPPORTED_FIELDS)[0];

 */
package org.codelibs.fess.exception;

import jakarta.servlet.ServletException;

/**
 * Runtime exception wrapper for ServletException.
 *
 * This exception is used to wrap checked ServletExceptions and convert them
 * into unchecked RuntimeExceptions, allowing them to be thrown from methods
 * that don't declare ServletException in their throws clause.
 */
public class ServletRuntimeException extends RuntimeException {

                    return singletonMap(entry.getKey(), entry.getValue());
                default:
                    return new MapN<>(map);
            }
        }
    }

    @SuppressWarnings("unchecked")
    static <K, V> Map<K, V> emptyMap() {
        return (Map<K, V>) EMPTY_MAP;
    }

    static <K, V> Map<K, V> singletonMap(K key, V value) {
        return new Map1<>(key, value);
    }

 *
 * @author Louis Wasserman
 */
@GwtIncompatible
public final class SafeTreeSet<E> implements Serializable, NavigableSet<E> {
  @SuppressWarnings("unchecked")
  private static final Comparator<Object> NATURAL_ORDER =
      (o1, o2) -> ((Comparable<Object>) o1).compareTo(o2);

  private final NavigableSet<E> delegate;

  public SafeTreeSet() {
    this(new TreeSet<E>());

    /** Gets the weak value reference held by entry. */
    WeakValueReference<K, V, E> getValueReference();
  }

  @SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
  static <K, V, E extends InternalEntry<K, V, E>>
      WeakValueReference<K, V, E> unsetWeakValueReference() {

    #; Flg = list:{
    #    ; map:{topComment=general boolean classification for every flg-column; codeType=Number}
    #    ; map:{code=1; name=True ; alias=Checked  ; comment=means yes; sisterCode=true}
    #    ; map:{code=0; name=False; alias=Unchecked; comment=means no ; sisterCode=false}
    #}
    # example for table classification
    #; MemberStatus = list:{

    JAPAN,
    SWITZERLAND,
    UK
  }

  @AndroidIncompatible // test-suite builders
  public static final class EnumHashBiMapGenerator implements TestBiMapGenerator<Country, String> {
    @SuppressWarnings("unchecked")
    @Override
    public BiMap<Country, String> create(Object... entries) {
      BiMap<Country, String> result = EnumHashBiMap.create(Country.class);
      for (Object o : entries) {

    }
  }

  @SuppressWarnings("unchecked") // C can only be @Nullable Character or Character
  protected @NonNull C cellValue(Character character) {
    return (C) character;
  }

  // Only safe wrt. ClassCastException. Not null-safe (can be used to test expected Table NPEs)
  @SuppressWarnings("unchecked")
  protected C nullableCellValue(@Nullable Character character) {