diff --git a/src/policy/src/main/java/eu/teraflow/policy/common/Util.java b/src/policy/src/main/java/eu/teraflow/policy/common/Util.java
new file mode 100644
index 0000000000000000000000000000000000000000..2fe37e47e806de047d53241bddead5b686bc5329
--- /dev/null
+++ b/src/policy/src/main/java/eu/teraflow/policy/common/Util.java
@@ -0,0 +1,13 @@
+package eu.teraflow.policy.common;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Util {
+
+    private Util() {}
+
+    public static <T> String toString(List<T> list) {
+        return list.stream().map(T::toString).collect(Collectors.joining(", "));
+    }
+}