'Determine the number of intervals passed as of the given point in
time.
@param t: The specified time (from the start of the L{LoopingCall}) to
be measured in intervals
@return: The C{int} number of intervals which have passed as of the
given point in time.'

def _intervalOf(self, t):

    elapsedTime = (t - self.starttime)
    intervalNum = int((elapsedTime / self.interval))
    return intervalNum
