Main.java:7: error: incompatible types: bad return type in lambda expression
IntStream.empty().flatMap(x -> Stream.of(LongStream.empty()));
^
no instance(s) of type variable(s) T exist so that Stream<T> conforms to IntStream
where T is a type-variable:
T extends Object declared in method <T>of(T)
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error