diff -r 34feeb53c0ba -r 0315d9983cd0 main_marking5/bf_test4b.scala
--- a/main_marking5/bf_test4b.scala	Sun Jan 15 10:58:13 2023 +0000
+++ b/main_marking5/bf_test4b.scala	Sat Mar 11 22:01:53 2023 +0000
@@ -1,5 +1,12 @@
 import M5a._
 
+
+import scala.concurrent._
+import scala.concurrent.duration._
+import ExecutionContext.Implicits.global
+import scala.language.postfixOps 
+
+lazy val f = Future {
 val urban_bench = 
 """>+[<+++++++++++++>-]<[[>+>+<<-]>[<+>-]++++++++
    [>++++++++<-]>.[-]<<>++++++++++[>++++++++++[>++
@@ -8,3 +15,7 @@
 
 assert(run(urban_bench, Map()) == 
   Map(0 -> 10, 5 -> 0, 1 -> 0, 6 -> 0, 2 -> 0, 7 -> 0, 3 -> 0, 4 -> 0))
+
+}
+
+Await.result(f, 32 second)