def test_timeintervaltools_TimeInterval_shift_to_rational_01():
r'''TimeInterval.shift_to_rational returns a new TimeInterval instance
unless offset is old start_offset offset.
'''
i1 = TimeInterval(3, 23)
i2 = i1.shift_to_rational(-1000)
assert i1 != i2
i2 = i1.shift_to_rational(3)
assert i1 == i2
def test_timeintervaltools_TimeInterval_shift_to_rational_03():
r'''TimeIntervals can be shifted by Fractions.
'''
i1 = TimeInterval(3, 23)
i2 = i1.shift_to_rational(Fraction(-51, 3))
assert i2.start_offset == Fraction(-51, 3)
assert i2.duration == i1.duration
def test_timeintervaltools_TimeInterval_shift_to_rational_02():
r'''TimeIntervals can be shifted by ints.
'''
i1 = TimeInterval(3, 23)
i2 = i1.shift_to_rational(-1)
assert i2.start_offset == -1
assert i2.duration == i1.duration