for (Object element : elements) {
        @SuppressWarnings("unchecked")
        Entry<String, Integer> entry = (Entry<String, Integer>) element;
        multimap.put(entry.getKey(), entry.getValue());
      }
      return multimap.entries();
    }

    abstract Multimap<String, Integer> createMultimap();

    @Override
    @SuppressWarnings("unchecked")
    public Entry<String, Integer>[] createArray(int length) {

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/** Static utility method for unchecked throwing of any {@link Throwable}. */
@GwtCompatible
final class SneakyThrows<T extends Throwable> {
  /**
   * Throws {@code t} as if it were an unchecked {@link Throwable}.
   *
   * <p>This method is useful primarily when we make a reflective call to a method with no {@code

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/** Static utility method for unchecked throwing of any {@link Throwable}. */
@GwtCompatible
final class SneakyThrows<T extends Throwable> {
  /**
   * Throws {@code t} as if it were an unchecked {@link Throwable}.
   *
   * <p>This method is useful primarily when we make a reflective call to a method with no {@code

                    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 Chris Povirk
 */
@GwtCompatible
@NullMarked
final class Platform {
  /** Serializes and deserializes the specified object. */
  @SuppressWarnings("unchecked")
  static <T> T reserialize(T object) {
    checkNotNull(object);
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    try {
      ObjectOutputStream out = new ObjectOutputStream(bytes);

        // These come from Entry<K, Collection<V>>> objects somewhere.
        @SuppressWarnings("unchecked")
        K key = (K) entry.getKey();
        keySet.add(key);
        for (Object v : (Collection<?>) entry.getValue()) {
          // These come from Entry<K, Collection<V>>> objects somewhere.
          @SuppressWarnings("unchecked")
          V value = (V) v;
          builder.add(mapEntry(key, value));
        }
      }

      Map<K, V> map, ObjectInputStream stream, int size)
      throws IOException, ClassNotFoundException {
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") // reading data stored by writeMap
      K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") // reading data stored by writeMap
      V value = (V) stream.readObject();
      map.put(key, value);
    }
  }

  /**

      if (info.getName().endsWith("_gwt")) {
        Class<?> clazz = info.load();
        // TODO(cpovirk): why does asSubclass() throw? Is it something about ClassLoaders?
        @SuppressWarnings("unchecked")
        Class<? extends GWTTestCase> cast = (Class<? extends GWTTestCase>) clazz;
        suite.addTestSuite(cast);
      }
    }
    return suite;
  }

/** Implementation of an {@link Optional} not containing a reference. */
@GwtCompatible
final class Absent<T> extends Optional<T> {
  static final Absent<Object> INSTANCE = new Absent<>();

  @SuppressWarnings("unchecked") // implementation is "fully variant"
  static <T> Optional<T> withType() {
    return (Optional<T>) INSTANCE;
  }

  private Absent() {}

  @Override
  public boolean isPresent() {
    return false;
  }

           * requireNonNull is safe because the first `2*(size+keyOffset)` elements have been filled
           * in.
           */
          @SuppressWarnings("unchecked")
          K key = (K) requireNonNull(alternatingKeysAndValues[2 * index + keyOffset]);
          @SuppressWarnings("unchecked")
          V value = (V) requireNonNull(alternatingKeysAndValues[2 * index + (keyOffset ^ 1)]);