protected function didApplyHeraldRules(PhabricatorLiskDAO $object, HeraldAdapter $adapter, HeraldTranscript $transcript)
 {
     $xactions = array();
     // Build a transaction to adjust reviewers.
     $reviewers = array(DifferentialReviewerStatus::STATUS_ADDED => array_keys($adapter->getReviewersAddedByHerald()), DifferentialReviewerStatus::STATUS_BLOCKING => array_keys($adapter->getBlockingReviewersAddedByHerald()));
     $old_reviewers = $object->getReviewerStatus();
     $old_reviewers = mpull($old_reviewers, null, 'getReviewerPHID');
     $value = array();
     foreach ($reviewers as $status => $phids) {
         foreach ($phids as $phid) {
             if ($phid == $object->getAuthorPHID()) {
                 // Don't try to add the revision's author as a reviewer, since this
                 // isn't valid and doesn't make sense.
                 continue;
             }
             // If the target is already a reviewer, don't try to change anything
             // if their current status is at least as strong as the new status.
             // For example, don't downgrade an "Accepted" to a "Blocking Reviewer".
             $old_reviewer = idx($old_reviewers, $phid);
             if ($old_reviewer) {
                 $old_status = $old_reviewer->getStatus();
                 $old_strength = DifferentialReviewerStatus::getStatusStrength($old_status);
                 $new_strength = DifferentialReviewerStatus::getStatusStrength($status);
                 if ($new_strength <= $old_strength) {
                     continue;
                 }
             }
             $value['+'][$phid] = array('data' => array('status' => $status));
         }
     }
     if ($value) {
         $edge_reviewer = DifferentialRevisionHasReviewerEdgeType::EDGECONST;
         $xactions[] = id(new DifferentialTransaction())->setTransactionType(PhabricatorTransactions::TYPE_EDGE)->setMetadataValue('edge:type', $edge_reviewer)->setNewValue($value);
     }
     // Require legalpad document signatures.
     $legal_phids = $adapter->getRequiredSignatureDocumentPHIDs();
     if ($legal_phids) {
         // We only require signatures of documents which have not already
         // been signed. In general, this reduces the amount of churn that
         // signature rules cause.
         $signatures = id(new LegalpadDocumentSignatureQuery())->setViewer(PhabricatorUser::getOmnipotentUser())->withDocumentPHIDs($legal_phids)->withSignerPHIDs(array($object->getAuthorPHID()))->execute();
         $signed_phids = mpull($signatures, 'getDocumentPHID');
         $legal_phids = array_diff($legal_phids, $signed_phids);
         // If we still have something to trigger, add the edges.
         if ($legal_phids) {
             $edge_legal = LegalpadObjectNeedsSignatureEdgeType::EDGECONST;
             $xactions[] = id(new DifferentialTransaction())->setTransactionType(PhabricatorTransactions::TYPE_EDGE)->setMetadataValue('edge:type', $edge_legal)->setNewValue(array('+' => array_fuse($legal_phids)));
         }
     }
     // Apply build plans.
     HarbormasterBuildable::applyBuildPlans($adapter->getDiff()->getPHID(), $adapter->getPHID(), $adapter->getBuildPlans());
     return $xactions;
 }