BitSetIndexToIndexMultiMap implements IndexToIndexMultiMap { @Override public String toString() { return "BitSetBasedIndexToIndexMultiMap{" + "keysCount=" + keysCount + '}'; } private  BitSetIndexToIndexMultiMap(
            final int keysCount,
            @NotNull
            final Buffer elements,
            final int bitSetSizeInLongs); @NotNull static BitSetIndexToIndexMultiMap from(
            @NotNull
            final Buffer buf); @Override boolean get(
            @NotNull
            final BitSet dest,
            final int key); @Override boolean getFrom(
            @NotNull
            final BitSet dest,
            final int fromInclusive); @Override boolean getTo(
            @NotNull
            final BitSet dest,
            final int toExclusive); @Override boolean getBetween(
            @NotNull
            final BitSet dest,
            final int fromInclusive,
            final int toExclusive); @Override int getKeysCount(); @Override String toString(); @NotNull @Override Iterator<IntToIntArray> ascending(
            @NotNull
            final BitSet valueFilter); @NotNull @Override Iterator<IntToIntArray> descending(
            @NotNull
            final BitSet valueFilter);  }
@Test public void string() throws IOException { final IndexToIndexMultiMap index = build(); assertTrue(index.toString().contains(Integer.toString(DOCS / 2))); }