* shared resources.
 *
 * @param <K> the most general type of keys this listener can listen for; for example {@code Object}
 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public interface RemovalListener<K, V> {

  }

  @SuppressWarnings("unchecked") // Safe because we only cast if key is found in map.
  @Override
  @Nullable V get(Object key) {
    checkNotNull(key);
    V value = getIfCached(key);
    if (value != null) {
      return value;
    }

    value = getWithoutCaching(key);
    if (value != null) {
      addToCache((K) key, value);
    }
    return value;
  }

        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            loadCount.incrementAndGet();
            return new Object();
          }

          @Override
          public ListenableFuture<Object> reload(Object key, Object oldValue) {
            reloadCount.incrementAndGet();
            return immediateFuture(new Object());
          }

    }

    /**
     * Returns whether the key is contained.
     *
     * @param key the key
     * @return whether the key is contained
     */
    public boolean containsKey(final String key) {
        return super.containsKey(convertKey(key));
    }

    @Override
    public V get(final Object key) {
        return super.get(convertKey(key));
    }

    @Override

      assertEquals(property.key() + "=" + property.value(), property.toString());
    }
  }

  public void testNoNullValues() {
    for (StandardSystemProperty property : StandardSystemProperty.values()) {
      // Even though the contract in System.getProperties() specifies that a value will exist for
      // all of the listed keys, for some reason the "java.compiler" key returns null in some JVMs.
      if (property == JAVA_COMPILER) {

          public Object load(Object key) throws Exception {
            return new Object();
          }

          @Override
          public Map<Object, Object> loadAll(Iterable<?> keys) throws Exception {
            Map<Object, Object> result = new HashMap<>();
            for (Object key : keys) {
              Object value = new Object();
              result.put(key, value);
              // add extra entries

     * Constructs a new AbstractExtractor.
     */
    public AbstractExtractor() {
        // NOP
    }

    /**
     * Registers this extractor with the ExtractorFactory.
     * @param keyList The list of keys to register this extractor under.
     */
    public void register(final List<String> keyList) {
        if (keyList == null || keyList.isEmpty()) {

- Range requests for GetObject/HeadObject for individual files from zip is not supported.
- Names inside ZIP files are kept unmodified, but some may lead to invalid paths. See [Object key naming guidelines](https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-keys.html) on safe names.
- This API behavior is limited for following **read** operations on files inside a zip archive:
  - `HeadObject`
  - `GetObject`
  - `ListObjectsV2`

 * but can be extended by registering a {@code org.apache.maven.api.spi.LanguageProvider}.
 * <p>
 * Implementation must have {@code equals()} and {@code hashCode()} implemented, so implementations of this interface
 * can be used as keys.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
@SuppressWarnings("checkstyle:InterfaceIsType")
public interface Language extends ExtensibleEnum {

    /**

				schema.err = fmt.Errorf("invalid polymorphic foreign keys %+v for %v on field %s", relation.foreignKeys,
					schema, field.Name)
			}
		}

		if primaryKeyField == nil {
			schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing primaryKey field",
				relation.FieldSchema, schema, field.Name)
			return
		}

		// use same data type for foreign keys
		if copyableDataType(primaryKeyField.DataType) {