class Artifact(EmbeddedDocument):
key = StringField(required=True)
type = StringField(required=True)
mode = StringField(choices=("input", "output"), default="output")
uri = StringField()
hash = StringField()
content_size = LongField()
timestamp = LongField()
type_data = EmbeddedDocumentField(ArtifactTypeData)
display_data = SafeSortedListField(ListField(UnionField((int, float, str))))
def __init__(self, *args, **kwargs):
super(ModelLabels,
self).__init__(field=UnionField(types=(int, NoneType)),
*args,
**kwargs)