diff --git a/core-java/src/main/java/com/baeldung/concurrent/skiplist/EventWindowSort.java b/core-java/src/main/java/com/baeldung/concurrent/skiplist/EventWindowSort.java
index 9eef00bd3f..3aca6b0147 100644
--- a/core-java/src/main/java/com/baeldung/concurrent/skiplist/EventWindowSort.java
+++ b/core-java/src/main/java/com/baeldung/concurrent/skiplist/EventWindowSort.java
@@ -4,17 +4,10 @@ import java.time.ZonedDateTime;
 import java.util.Comparator;
 import java.util.concurrent.ConcurrentNavigableMap;
 import java.util.concurrent.ConcurrentSkipListMap;
-import java.util.function.ToLongFunction;
 
 public class EventWindowSort {
-    private final ConcurrentSkipListMap<ZonedDateTime, String> events = new ConcurrentSkipListMap<>(Comparator.comparingLong(new ToLongFunction<ZonedDateTime>() {
-        @Override
-        public long applyAsLong(ZonedDateTime value) {
-            return value
-              .toInstant()
-              .toEpochMilli();
-        }
-    }));
+    private final ConcurrentSkipListMap<ZonedDateTime, String> events
+            = new ConcurrentSkipListMap<>(Comparator.comparingLong(value -> value.toInstant().toEpochMilli()));
 
     public void acceptEvent(Event event) {
         events.put(event.getEventTime(), event.getContent());
@@ -22,14 +15,14 @@ public class EventWindowSort {
 
     public ConcurrentNavigableMap<ZonedDateTime, String> getEventsFromLastMinute() {
         return events.tailMap(ZonedDateTime
-          .now()
-          .minusMinutes(1));
+                .now()
+                .minusMinutes(1));
     }
 
     public ConcurrentNavigableMap<ZonedDateTime, String> getEventsOlderThatOneMinute() {
         return events.headMap(ZonedDateTime
-          .now()
-          .minusMinutes(1));
+                .now()
+                .minusMinutes(1));
     }
 
 }