generate <nreq> requests taking a random amount of time between 0 and 0.5 seconds

def run(self):
        """
        generate <nreq> requests taking a random amount of time between 0 and 0.5 seconds
        """
        for i in xrange(self.nreq):
            req = '%s_%s' % (self.ident, i)
            pre_request(None, req)
            sleep(random() / 2)
            post_request(None, req)