Update server/src/main/java/org/opensearch/search/profile/query/Concu…

…rrentQueryProfileBreakdown.java

Co-authored-by: Andriy Redko <drreta@gmail.com>
Signed-off-by: Ticheng Lin <51488860+ticheng-aws@users.noreply.github.com>

server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdown.java

@@ -84,7 +84,8 @@ public Map<String, Long> toBreakdownMap() {
             // the new rewritten query. The sliceCollectorsToLeaves is empty because this breakdown for rewritten query gets created later
             // in search leaf path which doesn't have collector. Also, this is not needed since this breakdown is per leaf and there is no
             // concurrency involved.
-            assert contexts.size() == 1 : new OpenSearchException(
+            assert contexts.size() == 1 : "Unexpected size: "
+                    + contexts.size() + " of leaves breakdown in ConcurrentQueryProfileBreakdown of rewritten query for a leaf."
                 "Unexpected size: "
                     + contexts.size()
                     + " of leaves breakdown in ConcurrentQueryProfileBreakdown of rewritten query for a leaf."