@staticmethod
def _labels_by_step_newest(expanded_results):
    """
        Makes one channel per step, based on most recent channel entered.

        See also
        --------
            _expand_results
            _labels_by_step_oldest
            _labels_by_step_multiple
            labels_by_step

        Parameters
        ----------
        expanded_results : list of 3-tuples (int, int, frozenset)
            input events; the output of _expand_results (see details there)

        Returns
        -------
        list of 3-tuples (int, int, frozenset)
            events with ranges such that there is only one channel at any
            given step number, and that channel is the most recent entered
        """
    relabeled = []
    previous = expanded_results[0]
    for current in expanded_results[1:]:
        relabeled += [(previous[0], current[0], previous[2])]
        previous = current
    relabeled += [expanded_results[-1]]
    return relabeled
