Reports transform operations that may return null inside a Reactive Stream chain.
Reactive Streams don't support nullable values, which causes such code to fail.
The quick-fix suggests replacing map() with mapNotNull, which omits exceptions.
Example:
repository.findWithTailableCursorBy()
.map(e -> (Person)null)
.doOnNext(System.out::println)
After the quick-fix is applied:
repository.findWithTailableCursorBy()
.mapNotNull(e -> (Person)null)
.doOnNext(System.out::println)
New in 2019.3