Locking is from the future. Remove this comment.

includes/FeedsSource.inc

@@ -126,10 +126,7 @@ class FeedsSource extends FeedsConfigurable {
   }
 
   /**
-   * Import a feed: execute, fetching, parsing and processing stage.
-   *
-   * Lock a source before importing by using FeedsSource::lock(), after
-   * importing, release with FeedsSource::release().
+   * Import a feed: execute fetching, parsing and processing stage.
    *
    * @return
    *   FEEDS_BATCH_COMPLETE if the import process finished. A decimal between