cr fixes

Signed-off-by: chrislai <[email protected]>

Author: chriswlai

ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/tracing/MLAgentTracer.java

@@ -14,6 +14,7 @@
 import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
 import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.ml.repackage.com.google.common.annotations.VisibleForTesting;
 
 import lombok.extern.log4j.Log4j2;
 
@@ -36,7 +37,7 @@ public static synchronized void initialize(Tracer tracer, MLFeatureEnabledSettin
 
     public static synchronized MLAgentTracer getInstance() {
         if (instance == null) {
-            throw new IllegalStateException("MLAgentTracer is not initialized. Call initialize() first or check feature flag.");
+            throw new IllegalStateException("MLAgentTracer is not initialized. Call initialize() first or enable plugins.ml_commons.agent_tracing_feature_enabled setting.");
         }
         return instance;
     }
@@ -107,6 +108,7 @@ public Tracer getTracer() {
         return tracer;
     }
 
+    @VisibleForTesting
     static void resetForTest() {
         instance = null;
     }