More "check key" doc comments

Change-Id: Ide66bc396e811776a58fd6aa7c1af2337ea185bd

diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index 92bd0bd..3099dce 100755 (executable)
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -263,6 +263,8 @@ class WANObjectCache {
        /**
         * Fetch the value of a timestamp "check" key
         *
+        * Note that "check" keys won't collide with other regular keys
+        *
         * @param string $key
         * @return float|bool TS_UNIX timestamp of the key; false if not present
         */
@@ -283,6 +285,8 @@ class WANObjectCache {
         * avoid race conditions where dependent keys get updated with a
         * stale value (e.g. from a DB slave).
         *
+        * Note that "check" keys won't collide with other regular keys
+        *
         * @see WANObjectCache::get()
         *
         * @param string $key Cache key