revert async sample

sdk/digitaltwins/azure-digitaltwins-core/src/samples/java/com/azure/digitaltwins/core/AsyncSample.java

@@ -14,28 +14,19 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.nimbusds.jose.util.IOUtils;
 import reactor.core.publisher.Mono;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.Arrays;
 import java.util.Random;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
-import java.util.function.Consumer;
-import java.util.stream.Stream;
 
 public class AsyncSample
 {
     private static final ObjectMapper mapper = new ObjectMapper();
     private static final Random random = new Random();
 
-    public static void main(String[] args) throws InterruptedException, IOException {
+    public static void main(String[] args) throws InterruptedException, JsonProcessingException {
         String tenantId = System.getenv("TENANT_ID");
         String clientId = System.getenv("CLIENT_ID");
         String clientSecret = System.getenv("CLIENT_SECRET");
@@ -72,8 +63,6 @@ public static void main(String[] args) throws InterruptedException, IOException
             .setCustomProperties("TemperatureUnit", "Celsius");
         String dt_String = mapper.writeValueAsString(basicDigitalTwin);
 
-        System.out.println(">>>>" + dt_String);
-
         Mono<DigitalTwinsResponse<String>> sourceTwinWithResponseString = client.createDigitalTwinWithResponse(dtId_String, dt_String);
         sourceTwinWithResponseString.subscribe(
             result -> {