    argument lambda function, where
            0 &lt;= scale_fn(x) &lt;= 1 for all x &gt;= 0.
            mode paramater is ignored
        scale_mode: {&#39;cycle&#39;, &#39;iterations&#39;}.
            Defines whether scale_fn is evaluated on
            cycle number or cycle iterations (training
            iterations since start of cycle). Default is &#39;cycle&#39;.
        reduce_on_plateau (int): LR will be reduced after this many
                                 epochs with no improvement on valid