@Override
        public boolean hasNext() {
            return next != null;
        }
Provides a view of a set returned by the getXwithTrait methods so that only
shapes of a specific type are treated as present within the set.

@param <T> Type of shape to project out of the Set.
smithy-model/src/main/java/software/amazon/smithy/model/ShapeTypeFilteredSet.java