add error handling for the SubscribeTopics function call

Author: HamzaRahmani

examples/avro_generic_consumer_example/avro_generic_consumer_example.go

@@ -75,6 +75,10 @@ func main() {
 	}
 
 	err = c.SubscribeTopics(topics, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %v\n", err)
+		os.Exit(1)
+	}
 
 	run := true
 

examples/avro_specific_consumer_example/avro_specific_consumer_example.go

@@ -75,6 +75,10 @@ func main() {
 	}
 
 	err = c.SubscribeTopics(topics, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %v\n", err)
+		os.Exit(1)
+	}
 
 	run := true
 

examples/consumer_example/consumer_example.go

@@ -69,6 +69,10 @@ func main() {
 	fmt.Printf("Created Consumer %v\n", c)
 
 	err = c.SubscribeTopics(topics, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %v\n", err)
+		os.Exit(1)
+	}
 
 	run := true
 

examples/json_consumer_example/json_consumer_example.go

@@ -75,6 +75,10 @@ func main() {
 	}
 
 	err = c.SubscribeTopics(topics, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %v\n", err)
+		os.Exit(1)
+	}
 
 	run := true
 

examples/protobuf_consumer_example/protobuf_consumer_example.go

@@ -80,6 +80,10 @@ func main() {
 	deser.ProtoRegistry.RegisterMessage((&User{}).ProtoReflect().Type())
 
 	err = c.SubscribeTopics(topics, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %v\n", err)
+		os.Exit(1)
+	}
 
 	run := true
 

examples/stats_example/stats_example.go

@@ -63,6 +63,10 @@ func main() {
 	fmt.Printf("Created Consumer %v\n", c)
 
 	err = c.SubscribeTopics(topics, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %v\n", err)
+		os.Exit(1)
+	}
 
 	run := true