keras/src/optimizers/loss_scale_optimizer.py/LossScaleOptimizer/__init__
class LossScaleOptimizer:    def __init__(
        self,
        inner_optimizer,
        initial_scale=2.0**15,
        dynamic_growth_steps=2000,
        **kwargs,
    ):
        if not kwargs.pop("dynamic", True):
            raise ValueError(
                "LossScaleOptimizer no longer suports `dynamic=False`. "
                "Instead, simply set `loss_scale_factor` directly on the "
                "`inner_optimizer`."
            )
        super().__init__(learning_rate=0.0, **kwargs)
        self.inner_optimizer = inner_optimizer
        self.initial_scale = initial_scale
        self.dynamic_growth_steps = dynamic_growth_steps