Feature: Generate IterableAsserts for all generated Asserts

Start by tracing the assertion generator that creates FooAssert, then inspect how ListAssert and the assertThat entry points are produced. Compare the requested FooIterableAssert shape with the current generated output and decide how generated iterable assertions should be exposed. Done means generated assertions support the requested singleElement().hasName("Fool") usage without manual wrapper classes.

We would like to write something like this:

List<Foo> result;
assertThat(result).singleElement().hasName("Fool")

Now, we can generate FooAssert with the generator, but the ListAssert we get out of assertThat in this case does, of course, not known about the generated assertion; we get a regular ObjectAssert<Foo>.

We can work around this by creating something like this here:

public class FooIterableAssert
  extends AbstractIterableAssert<FooIterableAssert, Iterable<? extends Foo>, Foo, FooIterableAssert> {

  protected FooIterableAssert(Iterable<? extends Foo> foos, Class<?> selfType) {
    super(foos, selfType);
  }

  @Override
  protected FooAssert toAssert(Foo value, String description) {
    return new FooAssert(value);
  }

  @Override
  protected FooIterableAssert newAbstractIterableAssert(Iterable<? extends Foo> iterable) {
    return new FooIterableAssert(iterable, FooIterableAssert.class);
  }

  public static FooIterableAssert assertThat(List<Foo> foos) {
    return new FooIterableAssert(foos, FooIterableAssert.class);
  }
}

This has the feel of "should be a template" and "surely not only we want this", so I'm raising this issue. :)
I'm also not sure whether one would have/want to fiddle with the entrypoint methods in support of this.

PS: I was considering to use Lombok's @ExtensionMethod on ListAssert to add something like FooAssert singleFoo() to it. Unfortunately, it does not seem possible to get the actual value back from an Assert, so I was stuck there.