### Question:
DocValuesCollector extends SimpleCollector { public List<MatchingDocs> getMatchingDocs() { if ( docs != null && segmentHits > 0 ) { createMatchingDocs(); docs = null; scores = null; context = null; } return Collections.unmodifiableList( matchingDocs ); } DocValuesCollector();  DocValuesCollector( boolean keepScores ); LongValuesIterator getValuesIterator( String field ); IndexProgressor getIndexProgressor( String field, IndexProgressor.NodeValueClient client ); ValuesIterator getSortedValuesIterator( String field, Sort sort ); ValuesIterator getPagedSortedValuesIterator( String field, Sort sort, int pageSize, int page ); IndexHits<Document> getIndexHits( Sort sort ); int getTotalHits(); boolean isKeepScores(); @Override final void collect( int doc ); @Override boolean needsScores(); @Override void setScorer( Scorer scorer ); @Override void doSetNextReader( LeafReaderContext context ); List<MatchingDocs> getMatchingDocs();  }### Answer:
@Test void shouldStartWithEmptyMatchingDocs() { DocValuesCollector collector = new DocValuesCollector(); assertEquals( emptyList(), collector.getMatchingDocs() ); }