fix doc block

src/Drawer.php

@@ -75,7 +75,12 @@ class Drawer implements DrawerInterface {
   }
 
   /**
-   * {@inheritDoc}
+   * Attaches cache tags strings to our drawer.
+   *
+   * The drawer is not an actual cache entry, so it does
+   * not actually leverage these tags itself. Instead,
+   * the tags are appended to cache entries associated with
+   * any of it's slots.
    */
   private function populateCacheTags() {
     // If more tags are needed, can use Cache::buildTags