def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.get_id()
        return_obj.idref = obj.get_idref()
        return_obj.timestamp = obj.get_timestamp()
        if isinstance(obj, cls._binding_class): # ThreatActorType properties
            return_obj.version = obj.get_version() if obj.get_version() else cls._version
            return_obj.title = obj.get_Title()
            return_obj.description = StructuredText.from_obj(obj.get_Description())
            return_obj.short_description = StructuredText.from_obj(obj.get_Short_Description())
            return_obj.identity = Identity.from_obj(obj.get_Identity())
            return_obj.types = [Statement.from_obj(x) for x in obj.get_Type()]
            return_obj.motivations = [Statement.from_obj(x) for x in obj.get_Motivation()]
            return_obj.sophistications = [Statement.from_obj(x) for x in obj.get_Sophistication()]
            return_obj.intended_effects = [Statement.from_obj(x) for x in obj.get_Intended_Effect()]
            return_obj.planning_and_operational_supports = [Statement.from_obj(x) for x in obj.get_Planning_And_Operational_Support()]
            return_obj.observed_ttps = ObservedTTPs.from_obj(obj.get_Observed_TTPs())
            return_obj.associated_campaigns = AssociatedCampaigns.from_obj(obj.get_Associated_Campaigns())
            return_obj.associated_actors = AssociatedActors.from_obj(obj.get_Associated_Actors())
            return_obj.handling = Marking.from_obj(obj.get_Handling())
            return_obj.confidence = Confidence.from_obj(obj.get_Confidence())
            return_obj.information_source = InformationSource.from_obj(obj.get_Information_Source())
            return_obj.related_packages = RelatedPackageRefs.from_obj(obj.get_Related_Packages())

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.get_id()
        return_obj.idref = obj.get_idref()
        return_obj.timestamp = obj.get_timestamp() # not yet implemented

        if isinstance(obj, cls._binding_class): # TTPType properties
            return_obj.version = obj.get_version() or cls._version
            return_obj.title = obj.get_Title()
            return_obj.description = StructuredText.from_obj(obj.get_Description())
            return_obj.short_description = StructuredText.from_obj(obj.get_Short_Description())
            return_obj.information_source = InformationSource.from_obj(obj.get_Information_Source())
            return_obj.handling = Marking.from_obj(obj.get_Handling())
            return_obj.potential_coas = PotentialCOAs.from_obj(obj.get_Potential_COAs())
            return_obj.related_exploit_targets = RelatedExploitTargets.from_obj(obj.get_Related_Exploit_Targets())
            return_obj.vulnerabilities = [Vulnerability.from_obj(x) for x in obj.get_Vulnerability()]
            return_obj.weakness = [Weakness.from_obj(x) for x in obj.get_Weakness()]
            return_obj.configuration = [Configuration.from_obj(x) for x in obj.get_Configuration()]
            return_obj.related_packages = RelatedPackageRefs.from_obj(obj.get_Related_Packages())

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        from stix.common import StructuredText, InformationSource

        if not return_obj:
            raise ValueError("Must provide a return_obj argument")

        if not obj:
            raise ValueError("Must provide an obj argument")

        return_obj.id_ = obj.id
        return_obj.idref = obj.idref
        return_obj.timestamp = obj.timestamp

        # These may not be found on the input obj if it isn't a full
        # type definition (e.g., used as a reference)
        return_obj.version = getattr(obj, 'version', None)
        return_obj.title = getattr(obj, 'Title', None)
        return_obj.description = \
            StructuredText.from_obj(getattr(obj, 'Description', None))
        return_obj.short_description = \
            StructuredText.from_obj(getattr(obj, 'Short_Description', None))
        return_obj.information_source = \
            InformationSource.from_obj(getattr(obj, 'Information_Source', None))

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.id
        return_obj.idref = obj.idref
        return_obj.timestamp = obj.timestamp # not yet implemented

        if isinstance(obj, cls._binding_class): # TTPType properties
            return_obj.version = obj.version
            return_obj.title = obj.Title
            return_obj.description = StructuredText.from_obj(obj.Description)
            return_obj.short_description = StructuredText.from_obj(obj.Short_Description)
            return_obj.information_source = InformationSource.from_obj(obj.Information_Source)
            return_obj.handling = Marking.from_obj(obj.Handling)
            return_obj.potential_coas = PotentialCOAs.from_obj(obj.Potential_COAs)
            return_obj.related_exploit_targets = RelatedExploitTargets.from_obj(obj.Related_Exploit_Targets)
            return_obj.vulnerabilities = [Vulnerability.from_obj(x) for x in obj.Vulnerability]
            return_obj.weaknesses = [Weakness.from_obj(x) for x in obj.Weakness]
            return_obj.configuration = [Configuration.from_obj(x) for x in obj.Configuration]
            return_obj.related_packages = RelatedPackageRefs.from_obj(obj.Related_Packages)

        return return_obj

    def from_dict(cls, dict_repr, return_obj=None):
        if not dict_repr:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = dict_repr.get('id')
        return_obj.idref = dict_repr.get('idref')
        return_obj.timestamp = dict_repr.get('timestamp')
        return_obj.version = dict_repr.get('version', cls._version)
        return_obj.title = dict_repr.get('title')
        return_obj.description = StructuredText.from_dict(dict_repr.get('description'))
        return_obj.short_description = StructuredText.from_dict(dict_repr.get('short_description'))
        return_obj.time = Time.from_dict(dict_repr.get('time'))
        return_obj.victims = [Identity.from_dict(x) for x in dict_repr.get('victims', [])]
        return_obj.categories = [IncidentCategory.from_dict(x) for x in dict_repr.get('categories', [])]
        return_obj.attributed_threat_actors = AttributedThreatActors.from_dict(dict_repr.get('attributed_threat_actors'))
        return_obj.related_indicators = RelatedIndicators.from_dict(dict_repr.get('related_indicators'))
        return_obj.related_observables = RelatedObservables.from_dict(dict_repr.get('related_observables'))
        return_obj.related_incidents = RelatedIncidents.from_dict(dict_repr.get('related_incidents'))
        return_obj.intended_effects = [Statement.from_dict(x) for x in dict_repr.get('intended_effects', [])]
        return_obj.leveraged_ttps = LeveragedTTPs.from_dict(dict_repr.get('leveraged_ttps'))
        return_obj.affected_assets = [AffectedAsset.from_dict(x) for x in dict_repr.get('affected_assets', [])]
        return_obj.discovery_methdos = [DiscoveryMethod.from_dict(x) for x in dict_repr.get('discovery_methods', [])]
        return_obj.reporter = InformationSource.from_dict(dict_repr.get('reporter'))
        return_obj.responders = [InformationSource.from_dict(x) for x in dict_repr.get('responders', [])]
        return_obj.coordinators = [InformationSource.from_dict(x) for x in dict_repr.get('coordinators', [])]
        return_obj.external_ids = [ExternalID.from_dict(x) for x in dict_repr.get('external_ids', [])]
        return_obj.impact_assessment = ImpactAssessment.from_dict(dict_repr.get('impact_assessment'))
        return_obj.information_source = InformationSource.from_dict(dict_repr.get('information_source'))
        return_obj.security_compromise = SecurityCompromise.from_dict(dict_repr.get('security_compromise'))
        return_obj.confidence = Confidence.from_dict(dict_repr.get('confidence'))
        return_obj.coa_taken = [COATaken.from_dict(x) for x in dict_repr.get('coa_taken', [])]
        
        return return_obj

    def from_dict(cls, dict_repr, return_obj=None):
        if not dict_repr:
            return None

        if not return_obj:
            return_obj = cls()

        return_obj.id_ = dict_repr.get('id')
        return_obj.idref = dict_repr.get('idref')
        return_obj.timestamp = dict_repr.get('timestamp')
        return_obj.version = dict_repr.get('version')
        return_obj.title = dict_repr.get('title')
        return_obj.description = StructuredText.from_dict(dict_repr.get('description'))
        return_obj.short_description = StructuredText.from_dict(dict_repr.get('short_description'))
        return_obj.identity = Identity.from_dict(dict_repr.get('identity'))
        return_obj.types = [Statement.from_dict(x) for x in dict_repr.get('types', [])]
        return_obj.motivations = [Statement.from_dict(x) for x in dict_repr.get('motivations', [])]
        return_obj.sophistications = [Statement.from_dict(x) for x in dict_repr.get('sophistications', [])]
        return_obj.intended_effects = [Statement.from_dict(x) for x in dict_repr.get('intended_effects', [])]
        return_obj.planning_and_operational_supports = [Statement.from_dict(x)
                for x in dict_repr.get('planning_and_operational_supports', [])]
        return_obj.observed_ttps = ObservedTTPs.from_dict(dict_repr.get('observed_ttps'))
        return_obj.associated_campaigns = AssociatedCampaigns.from_dict(dict_repr.get('associated_campaigns'))
        return_obj.associated_actors = AssociatedActors.from_dict(dict_repr.get('associated_actors'))
        return_obj.handling = Marking.from_dict(dict_repr.get('handling'))
        return_obj.confidence = Confidence.from_dict(dict_repr.get('confidence'))
        return_obj.information_source = InformationSource.from_dict(dict_repr.get('information_source'))
        return_obj.related_packages = RelatedPackageRefs.from_dict(dict_repr.get('related_packages'))

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.id
        return_obj.idref = obj.idref
        return_obj.timestamp = obj.timestamp

        if isinstance(obj, cls._binding_class): # CourseOfActionType properties
            return_obj.version = obj.version
            return_obj.title = obj.Title
            return_obj.stage = VocabString.from_obj(obj.Stage)
            return_obj.type_ = VocabString.from_obj(obj.Type)
            return_obj.description = StructuredText.from_obj(obj.Description)
            return_obj.short_description = StructuredText.from_obj(obj.Short_Description)
            return_obj.objective = Objective.from_obj(obj.Objective)
            return_obj.parameter_observables = \
                    Observables.from_obj(obj.Parameter_Observables)
            return_obj.impact = Statement.from_obj(obj.Impact)
            return_obj.cost = Statement.from_obj(obj.Cost)
            return_obj.efficacy = Statement.from_obj(obj.Efficacy)
            return_obj.information_source = InformationSource.from_obj(obj.Information_Source)
            return_obj.handling = Marking.from_obj(obj.Handling)
            return_obj.related_coas = \
                    RelatedCOAs.from_obj(obj.Related_COAs)
            return_obj.related_packages = \
                    RelatedPackageRefs.from_obj(obj.Related_Packages)

        return return_obj

    def from_dict(cls, dict_repr, return_obj=None):
        if not dict_repr:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = dict_repr.get('id')
        return_obj.idref = dict_repr.get('idref')
        return_obj.timestamp = dict_repr.get('timestamp')
        return_obj.version = dict_repr.get('version')
        return_obj.title = dict_repr.get('title')
        return_obj.stage = VocabString.from_dict(dict_repr.get('stage'))
        return_obj.type_ = VocabString.from_dict(dict_repr.get('type'))
        return_obj.description = StructuredText.from_dict(dict_repr.get('description'))
        return_obj.short_description = StructuredText.from_dict(dict_repr.get('short_description'))
        return_obj.objective = Objective.from_dict(dict_repr.get('objective'))
        return_obj.parameter_observables = \
                Observables.from_dict(dict_repr.get('parameter_observables'))
        return_obj.impact = Statement.from_dict(dict_repr.get('impact'))
        return_obj.cost = Statement.from_dict(dict_repr.get('cost'))
        return_obj.efficacy = Statement.from_dict(dict_repr.get('efficacy'))
        return_obj.information_source = InformationSource.from_dict(dict_repr.get('information_source'))
        return_obj.handling = Marking.from_dict(dict_repr.get('handling'))
        return_obj.related_coas = \
                RelatedCOAs.from_dict(dict_repr.get('related_coas'))
        return_obj.related_packages = \
                RelatedPackageRefs.from_dict(dict_repr.get('related_packages'))

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.get_id()
        return_obj.idref = obj.get_idref()
        return_obj.timestamp = obj.get_timestamp()

        if isinstance(obj, cls._binding_class): # CourseOfActionType properties
            return_obj.version = obj.get_version() or cls._version
            return_obj.title = obj.get_Title()
            return_obj.stage = VocabString.from_obj(obj.get_Stage())
            return_obj.type_ = VocabString.from_obj(obj.get_Type())
            return_obj.description = StructuredText.from_obj(obj.get_Description())
            return_obj.short_description = StructuredText.from_obj(obj.get_Short_Description())
            return_obj.objective = Objective.from_obj(obj.get_Objective())
            return_obj.parameter_observables = \
                    Observables.from_obj(obj.get_Parameter_Observables())
            return_obj.impact = Statement.from_obj(obj.get_Impact())
            return_obj.cost = Statement.from_obj(obj.get_Cost())
            return_obj.efficacy = Statement.from_obj(obj.get_Efficacy())
            return_obj.information_source = InformationSource.from_obj(obj.get_Information_Source())
            return_obj.handling = Marking.from_obj(obj.get_Handling())
            return_obj.related_coas = \
                    RelatedCOAs.from_obj(obj.get_Related_COAs())
            return_obj.related_packages = \
                    RelatedPackageRefs.from_obj(obj.get_Related_Packages())

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.description = StructuredText.from_obj(obj.get_Description())
        return_obj.short_description = StructuredText.from_obj(obj.get_Short_Description())
        return_obj.applicability_confidence = Confidence.from_obj(obj.get_Applicability_Confidence())
        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.id
        return_obj.idref = obj.idref
        return_obj.timestamp = obj.timestamp
        
        if isinstance(obj, cls._binding_class):
            return_obj.version = obj.version
            return_obj.title = obj.Title
            return_obj.description = StructuredText.from_obj(obj.Description)
            return_obj.short_description = StructuredText.from_obj(obj.Short_Description)
            return_obj.time = Time.from_obj(obj.Time)
    
            if obj.Victim:
                return_obj.victims = [Identity.from_obj(x) for x in obj.Victim]
            if obj.Categories:
                return_obj.categories = [IncidentCategory.from_obj(x) for x in obj.Categories.Category]
            if obj.Intended_Effect:
                return_obj.intended_effects = [Statement.from_obj(x) for x in obj.Intended_Effect]
            if obj.Affected_Assets:
                return_obj.affected_assets = [AffectedAsset.from_obj(x) for x in obj.Affected_Assets.Affected_Asset]
            if obj.Discovery_Method:
                return_obj.discovery_methods = [DiscoveryMethod.from_obj(x) for x in obj.Discovery_Method]
            if obj.Reporter:
                return_obj.reporter = InformationSource.from_obj(obj.Reporter)
            if obj.Responder:
                return_obj.responders = [InformationSource.from_obj(x) for x in obj.Responder]
            if obj.Coordinator:
                return_obj.coordinators = [InformationSource.from_obj(x) for x in obj.Coordinator]
            if obj.External_ID:
                return_obj.external_ids = [ExternalID.from_obj(x) for x in obj.External_ID]
            if obj.Impact_Assessment:
                return_obj.impact_assessment = ImpactAssessment.from_obj(obj.Impact_Assessment)
            if obj.Information_Source:
                return_obj.information_source = InformationSource.from_obj(obj.Information_Source)
            if obj.Security_Compromise:
                return_obj.security_compromise = SecurityCompromise.from_obj(obj.Security_Compromise)
            
            return_obj.coa_taken = [COATaken.from_obj(x) for x in obj.COA_Taken]
            return_obj.confidence = Confidence.from_obj(obj.Confidence)
            return_obj.attributed_threat_actors = AttributedThreatActors.from_obj(obj.Attributed_Threat_Actors)
            return_obj.related_indicators = RelatedIndicators.from_obj(obj.Related_Indicators)
            return_obj.related_observables = RelatedObservables.from_obj(obj.Related_Observables)
            return_obj.leveraged_ttps = LeveragedTTPs.from_obj(obj.Leveraged_TTPs)
            return_obj.related_incidents = RelatedIncidents.from_obj(obj.Related_Incidents)
            return_obj.status = VocabString.from_obj(obj.Status)
            return_obj.handling = Marking.from_obj(obj.Handling)
            return_obj.history = History.from_obj(obj.History)
            
        return return_obj

    def from_dict(cls, dict_repr, return_obj=None):
        if not dict_repr:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.description = StructuredText.from_dict(dict_repr.get('description'))
        return_obj.short_description = StructuredText.from_dict(dict_repr.get('short_description'))
        return_obj.cce_id = dict_repr.get('cce_id')

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.title = obj.get_Title()
        return_obj.cce_id = obj.get_CCE_ID()
        return_obj.description = StructuredText.from_obj(obj.get_Description())
        return_obj.short_description = StructuredText.from_obj(obj.get_Short_Description())
        return return_obj

    def from_dict(cls, dict_repr, return_obj=None):
        if not dict_repr:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.description = StructuredText.from_dict(dict_repr.get('description'))
        return_obj.short_description = StructuredText.from_dict(dict_repr.get('short_description'))
        return_obj.applicability_confidence = Confidence.from_dict(dict_repr.get('applicability_confidence'))
        
        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.description = StructuredText.from_obj(obj.Description)
        return_obj.short_description = StructuredText.from_obj(obj.Short_Description)
        return_obj.cce_id = obj.CCE_ID

        return return_obj

    def from_obj(cls, obj, return_obj=None):
        if not obj:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = obj.id
        return_obj.title = obj.Title
        return_obj.description = StructuredText.from_obj(obj.Description)
        return_obj.short_description = StructuredText.from_obj(obj.Short_Description)

        return return_obj

    def from_dict(cls, d, return_obj=None):
        if not d:
            return None
        if return_obj is None:
            return_obj = cls()

        return_obj.timestamp = d.get('timestamp')
        return_obj.timestamp_precision = d.get('timestamp_precision')
        return_obj.source = StructuredText.from_dict(d.get('source'))
        return_obj.reference = d.get('reference')
        return_obj.confidence = Confidence.from_dict(d.get('confidence'))
        return_obj.description = StructuredText.from_dict(d.get('description'))
        return_obj.related_observables = RelatedObservables.from_dict(d.get('related_observables'))
        return return_obj

    def from_dict(cls, dict_repr, return_obj=None):
        if not dict_repr:
            return None
        if not return_obj:
            return_obj = cls()

        return_obj.id_ = dict_repr.get('id')
        return_obj.title = dict_repr.get('title')
        return_obj.description = StructuredText.from_dict(dict_repr.get('description'))
        return_obj.short_description = StructuredText.from_dict(dict_repr.get('short_description'))
        return_obj.types = [AttackerInfrastructureType.from_dict(x) for x in dict_repr.get('types', [])]
        return_obj.observable_characterization = Observables.from_dict(dict_repr.get('observable_characterization'))

        return return_obj

 def from_obj(cls, obj, return_obj=None):
     if not obj:
         return None
     if return_obj is None:
         return_obj = cls()
     
     return_obj.timestamp = obj.get_timestamp()
     return_obj.timestamp_precision = obj.get_timestamp_precision()
     return_obj.source = StructuredText.from_obj(obj.get_Source())
     return_obj.refernce = obj.get_Reference()
     return_obj.confidence = Confidence.from_obj(obj.get_Confidence())
     return_obj.description = StructuredText.from_obj(obj.get_Description())
     return_obj.related_observables = RelatedObservables.from_obj(obj.get_Related_Observables())
     return return_obj

 def description(self, value):
     '''Sets the value of the description property. If the value is an instance of basestring, 
     it will be coerced into an instance of StructuredText, with its 'text' property set to 
     the input value'''
     
     if isinstance(value, basestring):
         st = StructuredText()
         st.value = value
         self._description = st
     elif isinstance(value, StructuredText):
         self._description = value
     elif not value:
         self._description = None
     else:
         raise ValueError('value must be instance of StructuredText or basestring')