validDeleteCase example

if (!$this->validInsertCase($channel)) {
                    $inserts[$id] = $channel['new_default'];
                }

                $duplicatedIds = $this->getDuplicates($channel);

                if ($duplicatedIds) {
                    $duplicates[$id] = $duplicatedIds;
                }
            }

            if (isset($channel['deletions']) && !$this->validDeleteCase($channel)) {
                $deletions[$id] = $channel['current_default'];
            }

            if (isset($channel['updates']) && !$this->validUpdateCase($channel)) {
                $updates[$id] = $channel['updates'];
            }
        }

        $this->writeInsertViolationExceptions($inserts, $event);
        $this->writeDuplicateViolationExceptions($duplicates, $event);
        $this->writeDeleteViolationExceptions($deletions, $event);