'Initialize a session with a unique ID for that session.'

def __init__(self, site, uid, reactor=None):

    components.Componentized.__init__(self)
    if (reactor is None):
        from twisted.internet import reactor
    self._reactor = reactor
    self.site = site
    self.uid = uid
    self.expireCallbacks = []
    self.touch()
    self.sessionNamespaces = {}
