Make eventIds private instead of public

Change-Id: I2eb616a7ec21f3d8b8a5e66c318cc0a1b8d64e51

src/main/java/com/googlesource/gerrit/plugins/eventseiffel/cache/EiffelEventIdCacheImpl.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/cache/EiffelEventIdCacheImpl.java b/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/cache/EiffelEventIdCacheImpl.java
index fdd62b1..3bc237d 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/cache/EiffelEventIdCacheImpl.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/cache/EiffelEventIdCacheImpl.java
@@ -62,7 +62,7 @@
     };
   }
 
-  public LoadingCache<EventKey, Optional<UUID>> eventIds;
+  private LoadingCache<EventKey, Optional<UUID>> eventIds;
   private final EventIdCacheConfig cfg;
   private final EventStorage eventStorage;