@staticmethod
def _check_intervals(intervals):
    """Split phase intervals that go beyond phase 1"""
    if isinstance(intervals, tuple):
        intervals = [intervals]
    for phase_interval in intervals:
        if phase_interval[0] > phase_interval[1]:
            intervals.remove(phase_interval)
            intervals.append([phase_interval[0], 1])
            intervals.append([0, phase_interval[1]])
    return intervals
