@Override
    public void execute(PluginContext context) {
        if (context.getOriginalModel().isPresent() && context.getProjection().isPresent()) {
            context.getFileManifest().writeJson(NULLABILITY_REPORT_PATH, serializeReport(context));
        }
    }
Generates a JSON report that contains a mapping of every structure member to
whether the member is considered nullable in v1 and v2 implementations.
smithy-build/src/main/java/software/amazon/smithy/build/plugins/NullabilityReportPlugin.java