protected function proceedComment(array $comment, array $changeSet, $key)
    {
        $reviewer = $this->proceedPerson($comment['reviewer']);

        // A comment don`t have a unique identifier, so we must generate an ID on our own.
        // Changeset Id + Reviewer ID + Key + Timestamp. This combination is "unique enough".
        // Is this comment already in database?
        $commentRecord = $this->getGerritCommentByIdentifier(
            $changeSet['id'],
            $reviewer['id'],
            $comment['timestamp'],
            $key
        );
        if ($commentRecord === false) {
            $commentData = array(
                'changeset' => $changeSet['id'],
                'timestamp' => $comment['timestamp'],
                'reviewer' => $reviewer['id'],
                'message' => $comment['message'],
                'number' => $key
            );
            $this->getDatabase()->insertRecord(Database::TABLE_COMMENT, $commentData);

            $comment = $this->unsetKeys($comment, array('timestamp', 'reviewer', 'message'));
            $this->checkIfAllValuesWereProceeded($comment, 'Comment');
        }
    }