How to use the autovizwidget.autovizwidget.plotlygraphs.graphbase.GraphBase._get_x_y_values function in autovizwidget

def _get_x_values_labels(df, encoding):
        if encoding.y is None:
            series = df.groupby([encoding.x]).size()
            values = series.values.tolist()
            labels = series.index.tolist()
        else:
            labels, values = GraphBase._get_x_y_values(df, encoding)
        return values, labels

def _get_data(self, df, encoding):
        x_values, y_values = GraphBase._get_x_y_values(df, encoding)
        return [Scatter(x=x_values, y=y_values)]

def _get_data(self, df, encoding):
        x_values, y_values = GraphBase._get_x_y_values(df, encoding)
        return [Bar(x=x_values, y=y_values)]

def _get_data(self, df, encoding):
        x_values, y_values = GraphBase._get_x_y_values(df, encoding)
        return [Scatter(x=x_values, y=y_values, fill="tonexty")]

def _get_data(self, df, encoding):
        x_values, y_values = GraphBase._get_x_y_values(df, encoding)
        return [Scatter(x=x_values, y=y_values, mode='markers')]