Collect and map in Java8 Streams

Question

Is there a way to do something like this in Java 8? I have the following interface:

public interface MyInterface{
    String groupId();
    Integer value();
}

I want to write the following method

public static Map<String, List<Integer>> groupByGroupId(Collection<MyInterface> mis){
    //...
}

The thing is I cannot just do map on the stream as that I lose MyInterface information.

mis.stream().map(MyInterface::value) // lose groupId

Also it's unacceptable to iterate over the collection twice. I mean I could apply groupingBy to get Map<String, MyInterface>

mis.stream.collect(
    groupingBy(
        MyInterface::groupId
    )
)

But with such approach I have to iterate over the resulting map to get what I want. Maybe there is something I could use with

groupingBy(classifier, downstreamCollector)

But could not find a collector which collects and does mapping while collecting. Is there anything in JDK to achieve this without lots pain?