// MatchAllDocsQuery is for "browsing" (counts facets
// for all non-deleted docs in the index); normally
// you'd use a "normal" query:
FacetsCollector.search(searcher, new MatchAllDocsQuery(), 10, fc);
Facets facets = new LongRangeFacetCounts("timestamp", fc,
PAST_HOUR,
PAST_SIX_HOURS,
PAST_DAY);
return facets.getTopChildren(10, "timestamp");
}