Why is Guava's EventBus marked unstable in IntelliJ 2018.2?

Question

A new inspection was added in IntelliJ 2018.2 which should warn from unstable APIs: https://youtrack.jetbrains.com/issue/IDEA-159541.

This warning shows up for the Guava's EventBus. Why is this an unstable API?

Answer 1

Because the EventBus class is annotated as @Beta.

You'd have to ask the Guava project maintainers why a class that exists for 16 versions of Guava is still Beta, but it still is.

Answer 2

Besides @JB Nizet's answer that perfectly explains why IntelliJ flags this error, you may also want to suppress it globally but only for the Google Beta annotations.

Just go to Settings -> Editor -> Inspections -> JVM languages as per the picture below and, if you feel like it, delete the com.google.common.anotations.Beta.

Answer 3

You can also ask IntelliJ to suppress the warning for the definition of your @Beta annotated class as follows:

@SuppressWarnings("UnstableApiUsage")
static RateLimiter API_RATE_LIMITER = RateLimiter.create(8);

This properly deals with the warning in a particular case when you're okay with using the class anyway (and don't run into issues).

Answer 4

EventBus class is marked with the @com.google.common.annotations.Beta annotation. So I think the inspection is triggering on that. See: https://google.github.io/guava/releases/22.0/api/docs/com/google/common/eventbus/EventBus.html