inline fun <T> List<T>.joinToString(separator: String, append: (it: T, StringBuilder) -> Unit): String
Joins all elements of this list by calling append and separates the elements with the given separator.
inline fun <T> List<T>.joinToString(separator: String, lastSeparator: String, append: (it: T, StringBuilder) -> Unit): String
Joins all elements of this list by calling append and separates the elements with the given separator whereas lastSeparator is used to separate the last and the second last element.