def axis_titles(self, x=None, y=None):
        """Apply axis titles to the figure.

        This is a convenience method for manually modifying the "Axes" mark.

        Parameters
        ----------
        x: string, default 'null'
            X-axis title
        y: string, default 'null'
            Y-axis title

        Example
        -------
        >>>vis.axis_titles(y="Data 1", x="Data 2")

        """
        keys = self.axes.get_keys()

        if keys:
            for key in keys:
                if key == 'x':
                    self.axes[key].title = x
                elif key == 'y':
                    self.axes[key].title = y
        else:
            self.axes.extend([Axis(type='x', title=x),
                              Axis(type='y', title=y)])
        return self
dataset/ETHPy150Open wrobstory/vincent/vincent/visualization.py/Visualization.axis_titles/original