--- a/src/name/blackcap/exifwasher/Whitelist.kt	Wed Apr 01 14:23:54 2020 -0700
+++ b/src/name/blackcap/exifwasher/Whitelist.kt	Wed Apr 08 20:29:12 2020 -0700
@@ -7,7 +7,7 @@
 import kotlin.collections.mutableSetOf
 import kotlin.collections.mutableListOf
 
-class Whitelist {
+class Whitelist: Cloneable {
     private val entire = mutableSetOf<String>()
     private val prefixes = mutableListOf<String>()
 
@@ -29,17 +29,18 @@
 
     fun contains(s: String) = entire.contains(s) || prefixes.find { s.startsWith(it) } != null
 
-    fun toList(): List<String> = mutableListOf<String>().also {
-        it.addAll(entire)
-        it.addAll(prefixes)
-        it.sort()
-    }
+    fun toList(): List<String> = prefixes + entire
 
     override fun toString(): String = toList().joinToString(",")
 
+    override public fun clone() = this().also { new ->
+        entire.forEach { new.addEntire(it) }
+        prefixes.forEach { new.addPrefix(it) }
+    }
+
     companion object {
         private val SPLITTER = Pattern.compile(",\\s*")
-        fun parse(raw: String) = Whitelist().also { 
+        fun parse(raw: String) = this().also {
             for (s in raw.split(SPLITTER)) {
                 it.add(s)
             }