ValueAnnotation

class ValueAnnotation(AbstractAnnotation, ABC):
    class Variant(Enum):
        CONSTANT = "constant"
        OMITTED = "omitted"
        OPTIONAL = "optional"
        REQUIRED = "required"

    class DefaultValueType(Enum):
        BOOLEAN = "boolean"
        NONE = "none"
        NUMBER = "number"
        STRING = "string"

    variant: Variant

    @staticmethod
    def from_json(json: Any) -> ValueAnnotation:
        variant = json["variant"]
        if ValueAnnotation.Variant.CONSTANT.value == variant:
            return ConstantAnnotation.from_json(json)
        if ValueAnnotation.Variant.OMITTED.value == variant:
            return OmittedAnnotation.from_json(json)
        if ValueAnnotation.Variant.OPTIONAL.value == variant:
            return OptionalAnnotation.from_json(json)
        if ValueAnnotation.Variant.REQUIRED.value == variant:
            return RequiredAnnotation.from_json(json)
        raise Exception("unkonwn variant found")