def METHOD_NAME(self):
    self.assertFnMatch(
        obt.PiecewiseLinearFn.from_string("1.0"), {0: 1, 100: 1, 500: 1, 1000: 1}
    )
    self.assertFnMatch(
        obt.PiecewiseLinearFn.from_string("0:1,1000:0"),
        {0: 1, 500: 0.5, 1000: 0, 2000: 0},
    )
    self.assertFnMatch(
        obt.PiecewiseLinearFn.from_string("0:0,1000:1"),
        {0: 0, 500: 0.5, 1000: 1, 2000: 1},
    )
    self.assertFnMatch(
        obt.PiecewiseLinearFn.from_string("0:0,1000:1,2000:0"),
        {0: 0, 500: 0.5, 1000: 1, 1500: 0.5, 2000: 0, 3000: 0},
    )