There are cases where the result of a stream should have *exactly* one element. The findAny() operation will get the element, but this loses two ways: 1) it returns an optional which *should* have a value always present, so one has to do a getOrThrow(); 2) if there is more than one element, this fact is lost.

An alternative would be

    List<T> list = stream.<operation>.<operation>. ...
        .limit(2)
        .collect(toList());
    assert list.size() == 1;
    T result = list.get(0);

This is fairly cumbersome.

This function could be expressed as a terminal operation, e.g. stream.findOnly(), or it could be expressed as a collector, e.g. stream.collect(onlyElement()).