No sources available for REVRobotics libraries in Java

I have added the libraries for SPARK MAX to our project but I can’t access its sources. I get a comment in every class saying:

Failed to get sources. Instead, stub sources have been generated by the disassembler.
Implementation of methods is unavailable.

Is there any way to solve this? I know there is online documentation published, but it’s much easier to work with built-in documentation than to look it up online.

Thanks!