diff --git a/core-java-modules/core-java-concurrency-2/src/test/java/com/baeldung/concurrent/completablefuture/CombiningCompletableFuturesUnitTest.java b/core-java-modules/core-java-concurrency-2/src/test/java/com/baeldung/concurrent/completablefuture/CombiningCompletableFuturesUnitTest.java
index dbf8b98092..2c157b3ab2 100644
--- a/core-java-modules/core-java-concurrency-2/src/test/java/com/baeldung/concurrent/completablefuture/CombiningCompletableFuturesUnitTest.java
+++ b/core-java-modules/core-java-concurrency-2/src/test/java/com/baeldung/concurrent/completablefuture/CombiningCompletableFuturesUnitTest.java
@@ -51,7 +51,7 @@ public class CombiningCompletableFuturesUnitTest {
         // When all CompletableFutures are completed (exceptionally or otherwise)...
         Map<Boolean, List<Long>> resultsByValidity = clientCalls.stream()
             .map(this::handleFuture)
-            .collect(Collectors.partitioningBy(this::isValidResponse));
+            .collect(Collectors.partitioningBy(resourceId -> resourceId != -1L));
 
         // Then the returned resource identifiers should match what is expected...
         List<Long> validResults = resultsByValidity.getOrDefault(true, List.of());
@@ -64,10 +64,6 @@ public class CombiningCompletableFuturesUnitTest {
             .error(eq("Encountered error: java.lang.IllegalArgumentException: Bad Resource"));
     }
 
-    private boolean isValidResponse(long resourceId) {
-        return resourceId != -1L;
-    }
-
     /**
      * Completes the given CompletableFuture, handling any exceptions that are thrown.
      * @param future the CompletableFuture to complete.