Add note to v2.16.17 indicating the breaking change on API
A breaking change was introduced in v2.16.17 with Change-Id: I6c0f816
but the release notes were not adequately updated with the
entry in the dedicated section at the beginning.
Change-Id: I6e08ac4bc2fa3d4418880804e2f042eb6be623bd
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index f15e54e..a39ab2e 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -1151,6 +1151,13 @@
Plugins that use this annotation must be adjusted.
+ * `EnumSet` replaced with `Set` in all plugin API
+
+ All the plugins API have been amended to avoid the use of concrete class
+ `EnumSet` in their method signatures. Source-level compatibility is preserved
+ because `Set` is a super-class of `EnumSet`. However, existing plugins would
+ fail with NoSuchMethodException unless they are rebuilt against the new APIs.
+
* New Features
* Add support for Elasticsearch 7.6.x.
