code: def add_plot_boundary(ax, padding=0.125):
      
      nodes = np.asfortranarray(
          np.vstack([line.get_xydata() for line in ax.lines]).T
      )
      left, right, bottom, top = _helpers.bbox(nodes)
      center_x = 0.5 * (right + left)
      delta_x = right - left
      center_y = 0.5 * (top + bottom)
      delta_y = top - bottom
      multiplier = (1.0 + padding) * 0.5
      ax.set_xlim(
          center_x - multiplier * delta_x, center_x + multiplier * delta_x
      )
      ax.set_ylim(
          center_y - multiplier * delta_y, center_y + multiplier * delta_y
      )
docs: Add a buffer of empty space around a plot boundary.
  
      .. note::
  
         This only uses ``line`` data from the axis. It **could**
         use ``patch`` data, but doesn't at this time.
  
      Args:
          ax (matplotlib.artist.Artist): A matplotlib axis.
          padding (Optional[float]): Amount (as a fraction of width and height)
              of padding to add around data. Defaults to ``0.125``.