'Construct a new :class:`.ScopedRegistry`.
:param createfunc:  A creation function that will generate
a new value for the current scope, if none is present.
:param scopefunc:  A function that returns a hashable
token representing the current scope (such as, current
thread identifier).'

def __init__(self, createfunc, scopefunc):

    self.createfunc = createfunc
    self.scopefunc = scopefunc
    self.registry = {}
