private InternalSelector parseSelectorDirectedReverseNeighbor() {
        List<String> relationships = parseSelectorDirectedRelationships();
        expect('-');
        return NeighborSelector.reverse(relationships);
    }
Filter out unnecessary identity selectors when creating the finalized AST to evaluate selectors.
smithy-model/src/main/java/software/amazon/smithy/model/selector/SelectorParser.java