1 files changed, 12 insertions, 0 deletions
diff --git a/container-search/src/test/java/com/yahoo/search/dispatch/searchcluster/SearchClusterTest.java b/container-search/src/test/java/com/yahoo/search/dispatch/searchcluster/SearchClusterTest.java
index ad281aeda7d..840edd3a419 100644
--- a/container-search/src/test/java/com/yahoo/search/dispatch/searchcluster/SearchClusterTest.java
+++ b/container-search/src/test/java/com/yahoo/search/dispatch/searchcluster/SearchClusterTest.java
@@ -27,6 +27,7 @@ import static org.junit.Assert.assertTrue;
  * @author baldersheim
  */
 public class SearchClusterTest {
+    private static final double EPSILON = 0.00000000001;
 
     static class State implements AutoCloseable{
 
@@ -334,4 +335,15 @@ public class SearchClusterTest {
         assertEquals(3, node.getLastReceivedPongId());
     }
 
+    @Test
+    public void requireHitsAreEstimatedAccordingToPartitionsAndProbability() {
+        SearchCluster.TopKEstimator estimator = new SearchCluster.TopKEstimator(30, 0.999);
+        assertEquals(91.97368471911312, estimator.estimateExactK(200, 3), EPSILON);
+        assertEquals(92, estimator.estimateK(200, 3));
+        assertEquals(37.96328109101396, estimator.estimateExactK(200, 10), EPSILON);
+        assertEquals(38, estimator.estimateK(200, 10));
+        assertEquals(23.815737601023095, estimator.estimateExactK(200, 20), EPSILON);
+        assertEquals(24, estimator.estimateK(200, 20));
+    }
+
 }