diff --git a/server/src/test/java/org/opensearch/search/aggregations/AggregationsTests.java b/server/src/test/java/org/opensearch/search/aggregations/AggregationsTests.java
index 94fb6cded637d..050965b37c068 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/AggregationsTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/AggregationsTests.java
@@ -101,7 +101,6 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 import java.util.function.Predicate;
@@ -116,60 +115,56 @@
  *
  */
 public class AggregationsTests extends OpenSearchTestCase {
-    private static final List<InternalAggregationTestCase<?>> aggsTests = getAggsTests();
-
-    private static List<InternalAggregationTestCase<?>> getAggsTests() {
-        List<InternalAggregationTestCase<?>> aggsTests = new ArrayList<>();
-        aggsTests.add(new InternalCardinalityTests());
-        aggsTests.add(new InternalTDigestPercentilesTests());
-        aggsTests.add(new InternalTDigestPercentilesRanksTests());
-        aggsTests.add(new InternalHDRPercentilesTests());
-        aggsTests.add(new InternalHDRPercentilesRanksTests());
-        aggsTests.add(new InternalPercentilesBucketTests());
-        aggsTests.add(new InternalMinTests());
-        aggsTests.add(new InternalMaxTests());
-        aggsTests.add(new InternalAvgTests());
-        aggsTests.add(new InternalWeightedAvgTests());
-        aggsTests.add(new InternalSumTests());
-        aggsTests.add(new InternalValueCountTests());
-        aggsTests.add(new InternalSimpleValueTests());
-        aggsTests.add(new InternalDerivativeTests());
-        aggsTests.add(new InternalBucketMetricValueTests());
-        aggsTests.add(new InternalStatsTests());
-        aggsTests.add(new InternalStatsBucketTests());
-        aggsTests.add(new InternalExtendedStatsTests());
-        aggsTests.add(new InternalExtendedStatsBucketTests());
-        aggsTests.add(new InternalGeoCentroidTests());
-        aggsTests.add(new InternalHistogramTests());
-        aggsTests.add(new InternalDateHistogramTests());
-        aggsTests.add(new InternalAutoDateHistogramTests());
-        aggsTests.add(new InternalVariableWidthHistogramTests());
-        aggsTests.add(new LongTermsTests());
-        aggsTests.add(new DoubleTermsTests());
-        aggsTests.add(new StringTermsTests());
-        aggsTests.add(new LongRareTermsTests());
-        aggsTests.add(new StringRareTermsTests());
-        aggsTests.add(new InternalMissingTests());
-        aggsTests.add(new InternalNestedTests());
-        aggsTests.add(new InternalReverseNestedTests());
-        aggsTests.add(new InternalGlobalTests());
-        aggsTests.add(new InternalFilterTests());
-        aggsTests.add(new InternalSamplerTests());
-        aggsTests.add(new InternalRangeTests());
-        aggsTests.add(new InternalDateRangeTests());
-        aggsTests.add(new InternalGeoDistanceTests());
-        aggsTests.add(new InternalFiltersTests());
-        aggsTests.add(new InternalAdjacencyMatrixTests());
-        aggsTests.add(new SignificantLongTermsTests());
-        aggsTests.add(new SignificantStringTermsTests());
-        aggsTests.add(new InternalScriptedMetricTests());
-        aggsTests.add(new InternalBinaryRangeTests());
-        aggsTests.add(new InternalTopHitsTests());
-        aggsTests.add(new InternalCompositeTests());
-        aggsTests.add(new InternalMedianAbsoluteDeviationTests());
-        aggsTests.add(new InternalMultiTermsTests());
-        return Collections.unmodifiableList(aggsTests);
-    }
+    private static final List<InternalAggregationTestCase<?>> aggsTests = List.of(
+        new InternalCardinalityTests(),
+        new InternalTDigestPercentilesTests(),
+        new InternalTDigestPercentilesRanksTests(),
+        new InternalHDRPercentilesTests(),
+        new InternalHDRPercentilesRanksTests(),
+        new InternalPercentilesBucketTests(),
+        new InternalMinTests(),
+        new InternalMaxTests(),
+        new InternalAvgTests(),
+        new InternalWeightedAvgTests(),
+        new InternalSumTests(),
+        new InternalValueCountTests(),
+        new InternalSimpleValueTests(),
+        new InternalDerivativeTests(),
+        new InternalBucketMetricValueTests(),
+        new InternalStatsTests(),
+        new InternalStatsBucketTests(),
+        new InternalExtendedStatsTests(),
+        new InternalExtendedStatsBucketTests(),
+        new InternalGeoCentroidTests(),
+        new InternalHistogramTests(),
+        new InternalDateHistogramTests(),
+        new InternalAutoDateHistogramTests(),
+        new InternalVariableWidthHistogramTests(),
+        new LongTermsTests(),
+        new DoubleTermsTests(),
+        new StringTermsTests(),
+        new LongRareTermsTests(),
+        new StringRareTermsTests(),
+        new InternalMissingTests(),
+        new InternalNestedTests(),
+        new InternalReverseNestedTests(),
+        new InternalGlobalTests(),
+        new InternalFilterTests(),
+        new InternalSamplerTests(),
+        new InternalRangeTests(),
+        new InternalDateRangeTests(),
+        new InternalGeoDistanceTests(),
+        new InternalFiltersTests(),
+        new InternalAdjacencyMatrixTests(),
+        new SignificantLongTermsTests(),
+        new SignificantStringTermsTests(),
+        new InternalScriptedMetricTests(),
+        new InternalBinaryRangeTests(),
+        new InternalTopHitsTests(),
+        new InternalCompositeTests(),
+        new InternalMedianAbsoluteDeviationTests(),
+        new InternalMultiTermsTests()
+    );
 
     @Override
     protected NamedXContentRegistry xContentRegistry() {
@@ -226,7 +221,7 @@ public void testFromXContentWithRandomFields() throws IOException {
     private void parseAndAssert(boolean addRandomFields) throws IOException {
         XContentType xContentType = randomFrom(XContentType.values());
         final ToXContent.Params params = new ToXContent.MapParams(singletonMap(RestSearchAction.TYPED_KEYS_PARAM, "true"));
-        Aggregations aggregations = createTestInstance();
+        Aggregations aggregations = createTestInstance(1, 0, 3);
         BytesReference originalBytes = toShuffledXContent(aggregations, xContentType, params, randomBoolean());
         BytesReference mutated;
         if (addRandomFields) {