def METHOD_NAME(self, mine_guid, variance_guid):
    variance = Variance.find_by_mine_guid_and_variance_guid(mine_guid, variance_guid)
    if variance is None:
        raise NotFound('Unable to fetch variance')
    data = self.parser.parse_args()
    inspector_party_guid = data.get('inspector_party_guid')
    if inspector_party_guid:
        inspector = Party.find_by_party_guid(inspector_party_guid)
        if not inspector:
            raise BadRequest('Unable to find new inspector.')
        if not 'INS' in inspector.business_roles_codes:
            raise BadRequest('Party is not an inspector.')
        variance.inspector_party_guid = inspector_party_guid
    for key, value in data.items():
        if key in ['inspector_party_guid']:
            continue
        setattr(variance, key, value)
    # A manual check to prevent a stack trace dump on a foreign key /
    # constraint error because global error handling doesn't currently work
    # with these errors
    Variance.validate_status_with_other_values(
        status=variance.variance_application_status_code,
        issue=variance.issue_date,
        expiry=variance.expiry_date,
        inspector=variance.inspector_party_guid)
    variance.save()
    return variance