def iflat_tasks(self, status=None, op="==", nids=None):
        """
        Generator to iterate over all the tasks of the :class:`Flow`.

        If status is not None, only the tasks whose status satisfies
        the condition (task.status op status) are selected
        status can be either one of the flags defined in the :class:`Task` class
        (e.g Task.S_OK) or a string e.g "S_OK"
        nids is an optional list of node identifiers used to filter the tasks.
        """
        return self._iflat_tasks_wti(status=status, op=op, nids=nids, with_wti=False)