def METHOD_NAME(initial_value: float, gamma: float, current_step: int) -> float:
    """
    Decays the parameter value by gamma every step.
    Based on the closed form of ExponentialLR from Pytorch:
    https://pytorch.org/docs/stable/generated/torch.optim.lr_scheduler.ExponentialLR.html.
    Args:
        initial_value (float): Starting value of the parameter.
        gamma (float): Multiplicative factor of parameter value decay.
        current_step (int): Current step index.
    Returns:
        float: new parameter value
    """
    return initial_value * gamma**current_step