Removed unused imports

Author: garrix-fan

src/main/java/io/confluent/kafka/connect/datagen/DatagenTask.java

@@ -22,7 +22,6 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
@@ -35,11 +34,8 @@
 import java.util.concurrent.TimeoutException;
 import java.util.stream.Collectors;
 import org.apache.avro.generic.GenericRecord;
-import org.apache.kafka.connect.data.Field;
 import org.apache.kafka.connect.data.Schema;
 import org.apache.kafka.connect.data.SchemaAndValue;
-import org.apache.kafka.connect.data.SchemaBuilder;
-import org.apache.kafka.connect.data.Struct;
 import org.apache.kafka.connect.errors.ConnectException;
 import org.apache.kafka.connect.header.ConnectHeaders;
 import org.apache.kafka.connect.source.SourceRecord;