cleanup

Author: lens161

modules/dcache/src/main/java/org/dcache/util/Transfer.java

@@ -64,7 +64,12 @@
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.time.Duration;
-import java.util.*;
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.OptionalLong;
+import java.util.Optional;
+import java.util.Set;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;