public static <K,V,M extends Map<K,V>>Collector<Entry<K,V>,?,M> toMap(Supplier<M> mapSupplier){
  return Collectors.toMap(null,null,null,mapSupplier);
}

public static < K , V , M extends Map < K , V > > Collector < Entry < K , V > , ? , M > toMap ( Supplier < M > mapSupplier ) { return Collectors . toMap ( null , null , null , mapSupplier ) ; }
collect an map . entry stream into a map using the specified map supplier .
