def getJobGraphWhoseServicesAreRunning(self, maxWait):
        """
        :param float maxWait: Time in seconds to wait to get a jobGraph before returning
        :return: a jobGraph added to scheduleServices whose services are running, or None if
        no such job is available.
        :rtype: JobGraph
        """
        try:
            jobGraph = self._jobGraphsWithServicesThatHaveStarted.get(timeout=maxWait)
            self.jobGraphsWithServicesBeingStarted.remove(jobGraph)
            assert self.jobsIssuedToServiceManager >= 0
            self.jobsIssuedToServiceManager -= 1
            return jobGraph
        except Empty:
            return None