public FutureResult fill(Result result, String summaryClass) {
        return getFutureResult(execution.context().executor(), () -> {
            execution.fill(result, summaryClass);
            return result;
        }, result.getQuery());
    }
Fills this result and returns the future where it is filled.
container-search/src/main/java/com/yahoo/search/searchchain/AsyncExecution.java