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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def check(self, url_data):
 """Run all SSL certificate checks that have not yet been done. OpenSSL already checked the SSL notBefore and notAfter dates. """

        host = url_data.urlparts[1]
        if host in self.checked_hosts:
            return
        self.checked_hosts.add(host)
        cert = url_data.ssl_cert
        config = url_data.aggregate.config
        if cert and 'notAfter' in cert:
            self.check_ssl_valid_date(url_data, cert)
        elif config['sslverify']:
            msg = _('certificate did not include "notAfter" information')
            url_data.add_warning(msg)
        else:
            msg = _('SSL verification is disabled; enable the sslverify option')
            url_data.add_warning(msg)