My summary of the methods defined in http://hg.openjdk.java.net/lambda/lambda/jdk/file/tip/src/share/classes/java/util/Optional.java

Optional.java

interface Optional<T> {

  T get();

  boolean isPresent();

  void ifPresent(Consumer<? super T> consumer);

  T orElse(T other);

  T orElseGet(Supplier<? extends T> other);

  <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier) throws X;

}