fun setCallback(callback: (Int, String) -> Unit): Builder
set callback for result. this methods use higher-order functions. do not use this methods in java, use setCallback instead.
callback - higher-order functions which have two parameters, Int (resultCode) and String (path)
fun setCallback(callback: F2<Int, String>): Builder
set callback for result. this methods use F2 interface. use setCallback in Kotlin instead.