val upperIt2: (String) -> String = { s: String -> s.uppercase() + s.uppercase() }

// Simplify things with it
val upperIt3: (String) -> String = { it.uppercase() + it.uppercase() + it.uppercase() }

fun upperIt3(s: String): String = s.uppercase() + s.uppercase()

// Higher-order function as a parameter
fun func3(s: String, func: (String) -> String): String = func.invoke(s)