type Nspawn::Systemd::Bind = Variant[
  String,
  Tuple[String, String],
  # TODO Typecheck options
  Tuple[String, String, Array[String]],
  Struct[{
      'source'  => String,
      'dest'    => String,
      # TODO Typecheck options
      'options' => Optional[Array[String]],
  }],
]