@Override
        public Collection<? extends Shape> getStartingShapes(Model model) {
            return leftSelector.getStartingShapes(model);
        }
Maps input over a list of functions, passing the result of each to
the next.

<p>The list of selectors is short-circuited if any selector returns
an empty result (by virtue of a selector not forwarding a shape to
the next selector).
smithy-model/src/main/java/software/amazon/smithy/model/selector/AndSelector.java