Directly maps the agents and the tasks.

def doInteractions(self, number=1):
        """ Directly maps the agents and the tasks.
        """
        t0 = time.time()

        for _ in range(number):
            self._oneInteraction()

        elapsed = time.time() - t0
        logger.info("%d interactions executed in %.3fs." % (number, elapsed))

        return self.stepid