-import com.fasterxml.jackson.databind.ObjectMapper;
-import org.apache.kafka.common.serialization.*;
-import org.apache.kafka.streams.*;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.apache.kafka.streams.TestInputTopic;
+import org.apache.kafka.streams.TestOutputTopic;
+import org.apache.kafka.streams.Topology;
+import org.apache.kafka.streams.TopologyTestDriver;