def test_period_is_overlapping():
start = datetime.fromisoformat('2020-10-01T12:00:00')
end = datetime.fromisoformat('2020-10-01T13:00:00')
period1 = Period(start, end)
period2 = Period(start, end)
is_overlapping = period1.is_overlapped(period2)
assert is_overlapping == True
def test_period_is_overlapping_5():
start1 = datetime.fromisoformat('2020-10-01T12:00:00')
end1 = datetime.fromisoformat('2020-10-01T15:00:00')
period1 = Period(start1, end1)
start2 = datetime.fromisoformat('2020-10-01T15:00:00')
end2 = datetime.fromisoformat('2020-10-01T18:00:00')
period2 = Period(start2, end2)
is_overlapping = period1.is_overlapped(period2)
assert is_overlapping == True