* interface.
 *
 * <p>The {@link Suppliers} class provides common suppliers and related utilities.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/FunctionalExplained">the use of functional types</a>.
 *
 * <h3>For Java 8+ users</h3>
 *
 * <p>This interface is now a legacy type. Use {@code java.util.function.Supplier} (or the

   *
   * @param <K> the key type of the input and output entries
   * @param <V1> the value type of the input entry
   * @param <V2> the value type of the output entry
   * @since 7.0
   */
  public interface EntryTransformer<
      K extends @Nullable Object, V1 extends @Nullable Object, V2 extends @Nullable Object> {
    /**
     * Determines an output value based on a key-value pair. This method is <i>generally

      ImmutableListMultimap<K, V> delegate) {
    return checkNotNull(delegate);
  }

  /**
   * Returns an unmodifiable view of the specified collection, preserving the interface for
   * instances of {@code SortedSet}, {@code Set}, {@code List} and {@code Collection}, in that order
   * of preference.
   *
   * @param collection the collection for which to return an unmodifiable view

 * java.util.function.Function}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface Function<F extends @Nullable Object, T extends @Nullable Object>
{
  /**

        returned = true;
        return null;
      }
      throw new NoSuchElementException();
    }
  }

  /**
   * Adapts an {@code Enumeration} to the {@code Iterator} interface.
   *
   * <p>This method has no equivalent in {@link Iterables} because viewing an {@code Enumeration} as
   * an {@code Iterable} is impossible. However, the contents can be <i>copied</i> into a collection