SAMZA-2574: improve flexibility of SystemFactory interface
diff --git a/samza-core/src/main/java/org/apache/samza/util/DiagnosticsUtil.java b/samza-core/src/main/java/org/apache/samza/util/DiagnosticsUtil.java
index 0f7ff76..95fc60c 100644
--- a/samza-core/src/main/java/org/apache/samza/util/DiagnosticsUtil.java
+++ b/samza-core/src/main/java/org/apache/samza/util/DiagnosticsUtil.java
@@ -19,6 +19,7 @@
 package org.apache.samza.util;
 
 import java.io.File;
+import java.lang.invoke.MethodHandles;
 import java.time.Duration;
 import java.util.Optional;
 import org.apache.commons.lang3.tuple.ImmutablePair;