private function insertRegisteredUser(UserRegistered $payload)
{
$data = [];
$data['userIdentifier'] = $payload->userIdentifier()->toString();
$data['username'] = $payload->username()->toString();
$data['hashedPassword'] = $payload->hashedPassword()->toString();
$data['at'] = $payload->at()->format('Y-m-d H:i:s');
$this->connection->insert($this->table, $data);
}
