':param id: Target id
:type id: ``str``
:param name: Name of the target
:type name: ``str``
:param address: Hostname, FQDN, IP, file path etc.
:type address: ``str``
:param type: Backup target type (Physical, Virtual, ...).
:type type: :class:`.BackupTargetType`
:param driver: BackupDriver instance.
:type driver: :class:`.BackupDriver`
:param extra: (optional) Extra attributes (driver specific).
:type extra: ``dict``'

def __init__(self, id, name, address, type, driver, extra=None):

    self.id = (str(id) if id else None)
    self.name = name
    self.address = address
    self.type = type
    self.driver = driver
    self.extra = (extra or {})
