keras/src/optimizers/schedules/learning_rate_schedule.py/PiecewiseConstantDecay/__init__
class PiecewiseConstantDecay:    def __init__(self, boundaries, values, name="PiecewiseConstant"):
        super().__init__()

        if len(boundaries) != len(values) - 1:
            raise ValueError(
                "The length of boundaries should be 1 less than the length of "
                f"values. Received: boundaries={boundaries} of length "
                f"{len(boundaries)}, and values={values} "
                f"of length {len(values)}."
            )

        self.boundaries = boundaries
        self.values = values
        self.name = name