substringBeforeLast
fun String.substringBeforeLast(delimiter: Char, missingDelimiterValue: String = this): String(source)
fun String.substringBeforeLast(delimiter: String, missingDelimiterValue: String = this): String(source)
Returns a substring before the last occurrence of delimiter. If the string does not contain the delimiter, returns missingDelimiterValue which defaults to the original string.