assertEquals("training", Optional.of("training").get());
  }

  public void testOf_null() {
    assertThrows(NullPointerException.class, () -> Optional.of(null));
  }

  public void testFromNullable() {
    Optional<String> optionalName = Optional.fromNullable("bob");
    assertEquals("bob", optionalName.get());
  }

  public void testFromNullable_null() {
    // not promised by spec, but easier to test