@Test
public void _let_chain() {

    final String hello = "Hello ";
    final String world = "World";
    final String exclamation = "!";
    final String expected = hello + world + exclamation;
    final String returned = take(hello)
            ._let((in) -> in + world)
            ._let((in) -> in + exclamation)
            .unwrap();
    Assert.assertEquals(expected, returned);
}