public function getDsn(): string
  {
/*
  # File connection
  $connection = new PDO('sqlite:<filename>', null, null
    array(PDO::ATTR_PERSISTENT => true)
  );

  # Memory connection
  $connection = new PDO('sqlite::memory:', null, null
    array(PDO::ATTR_PERSISTENT => true)
  );
*/
    # Build the DSN
    $_dsn = $this->getDriver().':'.$this->getFilename();

    # Set it
    $this->setDsn($_dsn);

    return $_dsn;
  }