Use infix union operator

deob/src/main/java/dev/openrs2/deob/SignedClassUtils.kt

@@ -36,7 +36,7 @@ object SignedClassUtils {
         }
 
         // move loader signed classes to signlink
-        for (name in signedClasses.union(dependencies)) {
+        for (name in signedClasses union dependencies) {
             val `in` = loader.remove(name)!!
 
             val out = ClassNode()

deob/src/main/java/dev/openrs2/deob/analysis/IntInterpreter.kt

@@ -144,7 +144,7 @@ class IntInterpreter(private val parameters: Array<Set<Int>?>?) : Interpreter<In
             return IntValue.Unknown(basicValue)
         }
 
-        val set = value1.values.union(value2.values)
+        val set = value1.values union value2.values
         return if (set.size > MAX_TRACKED_VALUES) {
             IntValue.Unknown(basicValue)
         } else {