Plot the confusion matrix, with `title` and using `cmap`.

def plot_confusion_matrix(self, normalize:bool=False, title:str='Confusion matrix', cmap:Any="Blues", slice_size:int=1,
                              norm_dec:int=2, plot_txt:bool=True, return_fig:bool=None, **kwargs)->Optional[plt.Figure]:
        "Plot the confusion matrix, with `title` and using `cmap`."
        # This function is mainly copied from the sklearn docs
        cm = self.confusion_matrix(slice_size=slice_size)
        if normalize: cm = cm.astype('float') / cm.sum(axis=1)[:, np.newaxis]
        fig = plt.figure(**kwargs)
        plt.imshow(cm, interpolation='nearest', cmap=cmap)
        plt.title(title)
        tick_marks = np.arange(self.data.c)
        plt.xticks(tick_marks, self.data.y.classes, rotation=90)
        plt.yticks(tick_marks, self.data.y.classes, rotation=0)

        if plot_txt:
            thresh = cm.max() / 2.
            for i, j in itertools.product(range(cm.shape[0]), range(cm.shape[1])):
                coeff = f'{cm[i, j]:.{norm_dec}f}' if normalize else f'{cm[i, j]}'
                plt.text(j, i, coeff, horizontalalignment="center", verticalalignment="center", color="white" if cm[i, j] > thresh else "black")

        plt.tight_layout()
        plt.ylabel('Actual')
        plt.xlabel('Predicted')
        plt.grid(False)
        if ifnone(return_fig, defaults.return_fig): return fig