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native/src/main/java/io/ballerina/stdlib/observe/nativeimpl/OpenTracerBallerinaWrapper.java

@@ -184,6 +184,9 @@ public Object addTag(Environment env, String tagKey, String tagValue, long spanI
         if (spanId == -1) {
             ObserverContext observer = ObserveUtils.getObserverContextOfCurrentFrame(env);
             if (observer == null) {
+                // This is a case where the user has not started the tracing.
+                // ObserverContext will be null if function is executed without entry point like main or resource
+                // function ex. initialising phase.
                 return null;
             }
             span = observer.getSpan();