keras/src/dtype_policies/dtype_policy.py/QuantizedFloat8DTypePolicy/__init__
class QuantizedFloat8DTypePolicy:    def __init__(self, mode, source_name=None, amax_history_length=1024):
        super().__init__(mode=mode, source_name=source_name)
        if not isinstance(amax_history_length, int):
            raise TypeError(
                "`amax_history_length` must be an integer. "
                f"Received: amax_history_length={amax_history_length}"
            )
        self._amax_history_length = amax_history_length