extensionsForClass.kt

fun main(args: Array<String>) {
    val array = Class.forName("java.util.Collection")?.getInterfaces()!!
    for (c in array) {
        println(c)
        c!!.accept(ClassVisitor())
    }
}

class ClassVisitor

fun <T:Any?>java.lang.Class<out T>.accept(visitor: ClassVisitor) {
//    ...
}