'This extension allows for additional names to be associate with the
subject of the certificate. While it may contain a whole host of
possible names, it is usually used to allow certificates to be used
with multiple different domain names.
:return:
None or a GeneralNames object'

@property
def subject_alt_name_value(self):

    if (not self._processed_extensions):
        self._set_extensions()
    return self._subject_alt_name_value
