return old interval

Author: jackshirazi

inferred-spans/src/main/java/io/opentelemetry/contrib/inferredspans/InferredSpans.java

@@ -42,10 +42,11 @@ public static boolean isEnabled() {
    *
    * @param interval the new profiler interval
    */
-  public static void setProfilerInterval(Duration interval) {
+  public static Duration setProfilerInterval(Duration interval) {
     InferredSpansProcessor p = instance;
     if (p != null) {
-      p.setProfilerInterval(interval);
+      return p.setProfilerInterval(interval);
     }
+    return null;
   }
 }