'Create a pager with a Reference to a remote collector and
an optional callable to invoke upon completion.'

def __init__(self, collector, callback=None, *args, **kw):

    if callable(callback):
        self.callback = callback
        self.callbackArgs = args
        self.callbackKeyword = kw
    else:
        self.callback = None
    self._stillPaging = 1
    self.collector = collector
    collector.broker.registerPageProducer(self)
