fun main(args: Array<String>) {
    val funcs = Foo::class.declaredFunctions.filter { func ->
        func.parameters.any { param ->
            param.type.isSubtypeOf(Function::class.starProjectedType)
        }
    }

    println(funcs)
}

class Foo {
    fun <A> foo(fn: (A) -> Unit) {}
    fun <A, B> foo2(fn: (A, B) -> Unit) {}
    fun <A, B, C> foo3(fn: (A, B, C) -> Unit) {}

    fun notThisOne() { }
}