Weird error in IntelliJ IDEA


I’m subclassing DateTimeAxis like this:

new DateTimeAxis()



            public String getFormattedString(Date value) {

                return super.getFormattedString(new Date(-value.getTime()));



But IDEA is complaining that it must implement method e(U) in Axis. Sure enough, walking the type hierarchy in IDEA shows that Axis has a method e(U) that is abstract and it’s not actually implemented in DateTimeAxis. I’m a bit puzzled, how is this even working? 

NumberAxis is the same, but complaing about f(U).

Would it be possible to do something to remove the warning?


Hi Radu,

Thanks for bringing this to our attention - I can confirm I am able to get the same (or at least a similar) message in Eclipse. We’ll have to look into this issue further though I suspect it could be some kind of naming conflict brought about by obfuscation. I will of course keep you updated.

Kind regards and apologies for the inconvenience,



Hi Radu,

Just to update you on this issue - it was, as suspected, an issue with the obfuscation step of our release build. We’ll be providing a fix for this in the upcoming release, v1.5.

Kind regards,



Hi Radu,

We’ve now released v1.5 which contains a fix for this issue.

Kind regards,