How to use the asn1crypto.core.SequenceOf function in asn1crypto

class TBSRequestExtension(Sequence):
    _fields = [
        ('extn_id', TBSRequestExtensionId),
        ('critical', Boolean, {'default': False}),
        ('extn_value', ParsableOctetString),
    ]

    _oid_pair = ('extn_id', 'extn_value')
    _oid_specs = {
        'nonce': OctetString,
        'acceptable_responses': AcceptableResponses,
        'preferred_signature_algorithms': PreferredSignatureAlgorithms,
    }


class TBSRequestExtensions(SequenceOf):
    _child_spec = TBSRequestExtension


class TBSRequest(Sequence):
    _fields = [
        ('version', Version, {'explicit': 0, 'default': 'v1'}),
        ('requestor_name', GeneralName, {'explicit': 1, 'optional': True}),
        ('request_list', Requests),
        ('request_extensions', TBSRequestExtensions, {'explicit': 2, 'optional': True}),
    ]


class Certificates(SequenceOf):
    _child_spec = Certificate

class PostalCode(Choice):
    _alternatives = [
        ('numeric_code', NumericString),
        ('printable_code', PrintableString),
    ]


class PDSParameter(Set):
    _fields = [
        ('printable_string', PrintableString, {'optional': True}),
        ('teletex_string', TeletexString, {'optional': True}),
    ]


class PrintableAddress(SequenceOf):
    _child_spec = PrintableString


class UnformattedPostalAddress(Set):
    _fields = [
        ('printable_address', PrintableAddress, {'optional': True}),
        ('teletex_string', TeletexString, {'optional': True}),
    ]


class E1634Address(Sequence):
    _fields = [
        ('number', NumericString, {'tag_type': 'implicit', 'tag': 0}),
        ('sub_address', NumericString, {'tag_type': 'implicit', 'tag': 1, 'optional': True}),
    ]

'certificate_policies': CertificatePolicies,
        'policy_mappings': PolicyMappings,
        'authority_key_identifier': AuthorityKeyIdentifier,
        'policy_constraints': PolicyConstraints,
        'extended_key_usage': ExtKeyUsageSyntax,
        'freshest_crl': CRLDistributionPoints,
        'inhibit_any_policy': Integer,
        'authority_information_access': AuthorityInfoAccessSyntax,
        'subject_information_access': SubjectInfoAccessSyntax,
        'ocsp_no_check': Null,
        'entrust_version_extension': EntrustVersionInfo,
        'netscape_certificate_type': NetscapeCertificateType,
    }


class Extensions(SequenceOf):
    _child_spec = Extension


class Version(Integer):
    _map = {
        0: 'v1',
        1: 'v2',
        2: 'v3',
    }


class TbsCertificate(Sequence):
    _fields = [
        ('version', Version, {'tag_type': 'explicit', 'tag': 0, 'default': 'v1'}),
        ('serial_number', Integer),
        ('signature', SignedDigestAlgorithm),

_fields = [
        ('extn_id', CRLEntryExtensionId),
        ('critical', Boolean, {'default': False}),
        ('extn_value', ParsableOctetString),
    ]

    _oid_pair = ('extn_id', 'extn_value')
    _oid_specs = {
        'crl_reason': CRLReason,
        'hold_instruction_code': ObjectIdentifier,
        'invalidity_date': GeneralizedTime,
        'certificate_issuer': GeneralNames,
    }


class CRLEntryExtensions(SequenceOf):
    _child_spec = CRLEntryExtension


class RevokedCertificate(Sequence):
    _fields = [
        ('user_certificate', Integer),
        ('revocation_date', Time),
        ('crl_entry_extensions', CRLEntryExtensions, {'optional': True}),
    ]

    _processed_extensions = False
    _critical_extensions = None
    _crl_reason_value = None
    _invalidity_date_value = None
    _certificate_issuer_value = None
    _issuer_name = False

'group': SetOfIetfAttrSyntax,
        'role': SetOfRoleSyntax,
        'clearance': SetOfClearance,
        'timing_metrics': SetOfTimingMetrics,
        'timing_policy': SetOfTimingPolicy,
    }

    def _values_spec(self):
        return self._oid_specs.get(self['type'].native, SetOfAny)

    _spec_callbacks = {
        'values': _values_spec
    }


class AttCertAttributes(SequenceOf):
    _child_spec = AttCertAttribute


class AttributeCertificateInfoV2(Sequence):
    _fields = [
        ('version', AttCertVersion),
        ('holder', Holder),
        ('issuer', AttCertIssuer),
        ('signature', SignedDigestAlgorithm),
        ('serial_number', Integer),
        ('att_cert_validity_period', AttCertValidityPeriod),
        ('attributes', AttCertAttributes),
        ('issuer_unique_id', OctetBitString, {'optional': True}),
        ('extensions', Extensions, {'optional': True}),
    ]

('extn_value', ParsableOctetString),
    ]

    _oid_pair = ('extn_id', 'extn_value')
    _oid_specs = {
        'issuer_alt_name': GeneralNames,
        'crl_number': Integer,
        'delta_crl_indicator': Integer,
        'issuing_distribution_point': IssuingDistributionPoint,
        'authority_key_identifier': AuthorityKeyIdentifier,
        'freshest_crl': CRLDistributionPoints,
        'authority_information_access': AuthorityInfoAccessSyntax,
    }


class TBSCertListExtensions(SequenceOf):
    _child_spec = TBSCertListExtension


class CRLReason(Enumerated):
    _map = {
        0: 'unspecified',
        1: 'key_compromise',
        2: 'ca_compromise',
        3: 'affiliation_changed',
        4: 'superseded',
        5: 'cessation_of_operation',
        6: 'certificate_hold',
        8: 'remove_from_crl',
        9: 'privilege_withdrawn',
        10: 'aa_compromise',
    }

('private_domain_name', PrivateDomainName, {'tag_type': 'explicit', 'tag': 2, 'optional': True}),
        ('organization_name', PrintableString, {'tag_type': 'implicit', 'tag': 3, 'optional': True}),
        ('numeric_user_identifier', NumericString, {'tag_type': 'implicit', 'tag': 4, 'optional': True}),
        ('personal_name', PersonalName, {'tag_type': 'implicit', 'tag': 5, 'optional': True}),
        ('organizational_unit_names', OrganizationalUnitNames, {'tag_type': 'implicit', 'tag': 6, 'optional': True}),
    ]


class BuiltInDomainDefinedAttribute(Sequence):
    _fields = [
        ('type', PrintableString),
        ('value', PrintableString),
    ]


class BuiltInDomainDefinedAttributes(SequenceOf):
    _child_spec = BuiltInDomainDefinedAttribute


class TeletexDomainDefinedAttribute(Sequence):
    _fields = [
        ('type', TeletexString),
        ('value', TeletexString),
    ]


class TeletexDomainDefinedAttributes(SequenceOf):
    _child_spec = TeletexDomainDefinedAttribute


class PhysicalDeliveryCountryName(Choice):
    _alternatives = [

    @property
    def certificate_issuer_value(self):
        """
        This extension indicates the issuer of the certificate in question.

        :return:
            None or an x509.GeneralNames object
        """

        if self._processed_extensions is False:
            self._set_extensions()
        return self._certificate_issuer_value


class Responses(SequenceOf):
    _child_spec = SingleResponse


class ResponseDataExtensionId(ObjectIdentifier):
    _map = {
        '1.3.6.1.5.5.7.48.1.2': 'nonce',
        '1.3.6.1.5.5.7.48.1.9': 'extended_revoke',
    }


class ResponseDataExtension(Sequence):
    _fields = [
        ('extn_id', ResponseDataExtensionId),
        ('critical', Boolean, {'default': False}),
        ('extn_value', ParsableOctetString),
    ]

# class
UNIVERSAL = 0
APPLICATION = 1
CONTEXT = 2


class MechType(ObjectIdentifier):
	_map = {
		'1.3.6.1.4.1.311.2.2.10': 'NTLMSSP - Microsoft NTLM Security Support Provider',
		'1.2.840.48018.1.2.2'   : 'MS KRB5 - Microsoft Kerberos 5',
		'1.2.840.113554.1.2.2'  : 'KRB5 - Kerberos 5',
		'1.2.840.113554.1.2.2.3': 'KRB5 - Kerberos 5 - User to User',
		'1.3.6.1.4.1.311.2.2.30': 'NEGOEX - SPNEGO Extended Negotiation Security Mechanism',
}

class MechTypes(SequenceOf):
	_child_spec = MechType
	
class ContextFlags(BitString):
	_map = {
		0: 'delegFlag',
		1: 'mutualFlag',
		2: 'replayFlag',
		3: 'sequenceFlag',
		4: 'anonFlag',
		5: 'confFlag',
		6: 'integFlag',
}

class NegState(Enumerated):
	_map = {
		0: 'accept-completed',

class IssuerSerial(Sequence):
    _fields = [
        ('issuer', GeneralNames),
        ('serial_number', Integer),
    ]


class ESSCertID(Sequence):
    _fields = [
        ('cert_hash', OctetString),
        ('issuer_serial', IssuerSerial, {'optional': True}),
    ]


class ESSCertIDs(SequenceOf):
    _child_spec = ESSCertID


class SigningCertificate(Sequence):
    _fields = [
        ('certs', ESSCertIDs),
        ('policies', CertificatePolicies, {'optional': True}),
    ]


class SetOfSigningCertificates(SetOf):
    _child_spec = SigningCertificate


class ESSCertIDv2(Sequence):
    _fields = [