def test_insert(self): int1 = Interval(0, 0.5, 'a') int2 = Interval(0.75, 1, 'c') tier = IntervalTier('abc', 0, 1, [int1, int2]) tier.insert(0.5, 0.75, 'b') assert_is(tier[0], int1) assert_is(tier[2], int2) assert_equal(tier[1].xmin, 0.5) assert_equal(tier[1].xmax, 0.75) assert_equal(tier[1].text, 'b')