fun startHere() {
  for (index in 0..100) {
    var addResult = calculate(10, index, { x, y ->
      x + y
    })
    ...
  }
}
inline fun calculate(x: Int,
                     y: Int,
                     equation: (x: Int, y: Int) -> Int): Int {
  // Do something
  return equation(x, y)
}