git clone https://github.com/fesh0r/fernflower
gradle build
java -jar fernflower.jar out/production/kotlin-pocs/MainKt.class out
Download https://github.com/JetBrains/kotlin/releases/tag/v1.3.71
java -cp out/production/kotlin-pocs/;D:\webserver\tmp\kotlin-compiler\kotlinc\lib\kotlin-runner.jar MainKt