# MRJ Mania MRJ Mania introduces polyfills for Java 8 and above. The polyfills are powered using MRJ (multi-release-jar), thus practically nullifing all overhead (except maybe inlining costs, but those should be minimal) at runtime at the cost of a slightly bloated jar. Because this uses Java 9+'s multi-release-jar mechanism, this library won't work if the library is shaded and the uber-jar doesn't have `Multi-Release` set to `true` in the MANIFEST.MF file.