'Override parent class __init__ to enable setting of certDN
setting
@type certDN: string
@param certDN: Set the expected Distinguished Name of the
server to avoid errors matching hostnames.  This is useful
where the hostname is not fully qualified
@type hostname: string
@param hostname: hostname to match against peer certificate
subjectAltNames or subject common name
@type subj_alt_name_match: bool
@param subj_alt_name_match: flag to enable/disable matching of hostname
against peer certificate subjectAltNames.  Nb. A setting of True will
be ignored if the pyasn1 package is not installed'

def __init__(self, certDN=None, hostname=None, subj_alt_name_match=True):

    self.__certDN = None
    self.__hostname = None
    if (certDN is not None):
        self.certDN = certDN
    if (hostname is not None):
        self.hostname = hostname
    if subj_alt_name_match:
        if (not SUBJ_ALT_NAME_SUPPORT):
            log.warning('Overriding    "subj_alt_name_match"    keyword    setting:    peer    verification    with    subjectAltNames    is    disabled')
            self.__subj_alt_name_match = False
        else:
            self.__subj_alt_name_match = True
    else:
        log.debug('Disabling    peer    verification    with    subject    subjectAltNames!')
        self.__subj_alt_name_match = False
