UnixTime = NewType('UnixTime', float)

# Alternate output range for a device. Instead of outputting 0.0 to

# 1.0, you can map that range into, say, 0.2 to 0.7

OutputRange = NewType('OutputRange', Tuple[float, float])

_ObjType = TypeVar('_ObjType')

def _isSubclass2(t1: Type, t2: Type) -> bool:

    """same as issubclass but t1 can be a NewType"""

    if hasattr(t1, '__supertype__'):

    return issubclass(t1, t2)

def typedValue(objType: Type[_ObjType], graph, subj, pred) -> _ObjType:

    """graph.value(subj, pred) with a given return type. 

    If objType is not an rdflib.Node, we toPython() the value."""

    obj = graph.value(subj, pred)

    if obj is None:

        raise ValueError()

    conv = obj if _isSubclass2(objType, Node) else obj.toPython()

    return cast(objType, conv)