import java.util.*; | |
interface Stream<T> { | |
<R> Stream<R> map(Function<? super T, ? extends R> mapper); | |
} | |
interface Function<T, R> { | |
R apply(T t); | |
} | |
class Test1 | |
{ | |
public static void main(Stream<Map.Entry<String, Long>> stream) | |
{ | |
Stream<String> map = stream.map(Map.Entry::getKey); | |
} | |
} |