Merge pull request #12304 from Borzoo/beam-10499-nicer-tostring

[BEAM-10499] Adds a descriptive toString to SamzaRunner KeyedTimerData
diff --git a/runners/samza/src/main/java/org/apache/beam/runners/samza/runtime/KeyedTimerData.java b/runners/samza/src/main/java/org/apache/beam/runners/samza/runtime/KeyedTimerData.java
index a7e364d..46dc95a 100644
--- a/runners/samza/src/main/java/org/apache/beam/runners/samza/runtime/KeyedTimerData.java
+++ b/runners/samza/src/main/java/org/apache/beam/runners/samza/runtime/KeyedTimerData.java
@@ -99,6 +99,18 @@
   }
 
   @Override
+  public String toString() {
+    return "KeyedTimerData{"
+        + "key="
+        + key
+        + ", keyBytes="
+        + Arrays.toString(keyBytes)
+        + ", timerData="
+        + timerData
+        + '}';
+  }
+
+  @Override
   public boolean equals(@Nullable Object o) {
     if (this == o) {
       return true;