compSource = new DocIdDocComparatorSource();
} else if (SortField.FIELD_SCORE.equals(sf) || sf.getType() == SortField.Type.SCORE) {
// we want to do reverse sorting regardless for relevance
compSource = new ReverseDocComparatorSource(new RelevanceDocComparatorSource());
} else if (sf instanceof BoboCustomSortField) {
BoboCustomSortField custField = (BoboCustomSortField) sf;
DocComparatorSource src = custField.getCustomComparatorSource();
assert src != null;
compSource = src;
} else {
Set<String> facetNames = browser.getFacetNames();
String sortName = sf.getField();