protected function shouldGroupTransactions(PhabricatorApplicationTransaction $u, PhabricatorApplicationTransaction $v)
 {
     if ($u->getAuthorPHID() != $v->getAuthorPHID()) {
         // Don't group transactions by different authors.
         return false;
     }
     if ($v->getDateCreated() - $u->getDateCreated() > 60) {
         // Don't group if transactions that happened more than 60s apart.
         return false;
     }
     switch ($u->getTransactionType()) {
         case PhabricatorTransactions::TYPE_COMMENT:
         case PhabricatorAuditActionConstants::INLINE:
             break;
         default:
             return false;
     }
     switch ($v->getTransactionType()) {
         case PhabricatorAuditActionConstants::INLINE:
             return true;
     }
     return parent::shouldGroupTransactions($u, $v);
 }