'Move time on this clock forward by the given amount and run whatever
pending calls should be run.
@type amount: C{float}
@param amount: The number of seconds which to advance this clock\'s
time.'

def advance(self, amount):

    self.rightNow += amount
    self._sortCalls()
    while (self.calls and (self.calls[0].getTime() <= self.seconds())):
        call = self.calls.pop(0)
        call.called = 1
        call.func(*call.args, **call.kw)
        self._sortCalls()
