import Foo.bar

object Foo {

    fun bar(runnable: Runnable) {
        runnable.run()
    }
}

internal object Bar {
    @JvmStatic fun main(args: Array<String>) {
        bar(object : Runnable {
        override fun run() {
            doRun()
        }

        private fun doRun() {
            // Woo-hoo
        }
    })
    }
}