feat: avoid importing all

Author: samvazquez

src/main/java/org/dataloader/DataLoader.java

@@ -25,7 +25,11 @@
 import java.time.Clock;
 import java.time.Duration;
 import java.time.Instant;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.BiConsumer;