* Group id.
* @param string $mode
* Helps decide how to behave when there are conflicts.
- * A 'safe' value skips the merge if there are any un-resolved conflicts.
- * Does a force merge otherwise.
+ * A 'safe' value skips the merge if there are any un-resolved conflicts, wheras 'aggressive'
+ * mode does a force merge.
* @param bool $autoFlip to let api decide which contact to retain and which to delete.
* Whether to let api decide which contact to retain and which to delete.
* @param int $batchLimit number of merges to carry out in one batch.