Support a feature to convert a method into a function or predicate

[dakusui]

Introduce a feature, where following example is possible.

  public void chainExample() {
    String var = "hello, world";

    requireArgument(
        var,
        transform(
            chain("substring", 7)
                .andThen(chain("toUpperCase")))
            .castAndCheck(chainp("equals", "WORLD"))
    );
  }

Instead of defining a printable function every time, directly create it from a method.