function unshiftArticle(summary, article) {
    article = SummaryArticle(article);

    var parts = summary.getParts();
    var part = parts.get(0) || SummaryPart();

    var articles = part.getArticles();
    articles = articles.unshift(article);
    part = part.set('articles', articles);

    parts = parts.set(0, part);
    summary = summary.set('parts', parts);

    return indexLevels(summary);
}
function unshiftArticle(summary, article) {
    article = SummaryArticle(article);

    var parts = summary.getParts();
    var part = parts.get(0) || SummaryPart();

    var articles = part.getArticles();
    articles = articles.unshift(article);
    part = part.set('articles', articles);

    parts = parts.set(0, part);
    summary = summary.set('parts', parts);

    return indexLevels(summary);
}
function unshiftArticle ( summary , article ) { article = SummaryArticle ( article ) ; var parts = summary . getParts ( ) ; var part = parts . get ( 0 ) || SummaryPart ( ) ; var articles = part . getArticles ( ) ; articles = articles . unshift ( article ) ; part = part . set ( 'articles' , articles ) ; parts = parts . set ( 0 , part ) ; summary = summary . set ( 'parts' , parts ) ; return indexLevels ( summary ) ; }
Insert an article at the beginning of summary

@param {Summary} summary
@param {Article} article
@return {Summary}
Insert an article at the beginning of summary
unshift an article to the beginning of summary