Kotlin Compiler Rewrites the Code

A lot of it can be automated. There are a few things where manual changes have been made to the library code. We just do it once the Java Cs are already generated, methods on interfaces because that's supported in class files at this point. So we do that rewriting with D8 when you turn the class file into a dex file. Kotlin C does it at compile time. If you're targeting Java language level 1, 6, or 1, 7, so the Kotlin compiler has multiple target language settings. But these two things are very tightly connected. We can't push on Kotlin without pushing on Java as well.