docs: def finalize(self, **kwargs):
          """
          Finalize executes any subclass-specific axes finalization steps.
          The user calls poof and poof calls finalize.
  
          Parameters
          ----------
          kwargs: generic keyword arguments.
          """
          # Set the title on the plot
          self.set_title(
              'Prediction Error for {}'.format(self.name)
          )
  
          # Square the axes to ensure a 45 degree line
          if self.shared_limits:
              # Get the current limits
              ylim = self.ax.get_ylim()
              xlim = self.ax.get_xlim()
  
              # Find the range that captures all data
              bounds = (
                  min(ylim[0], xlim[0]),
                  max(ylim[1], xlim[1]),
              )
  
              # Reset the limits
              self.ax.set_xlim(bounds)
              self.ax.set_ylim(bounds)
  
              # Ensure the aspect ratio is square
              self.ax.set_aspect('equal', adjustable='box')
  
          # Draw the 45 degree line
          if self.identity:
              draw_identity_line(
                  ax=self.ax, ls='--', lw=2, c=self.colors['line'],
                  alpha=0.5, label="identity"
              )
  
          # Set the axes labels
          self.ax.set_ylabel(r'$\hat{y}$')
          self.ax.set_xlabel(r'$y$')
  
          # Set the legend
          # Note: it would be nice to be able to use the manual_legend utility
          # here, since if the user sets a low alpha value, the R2 color in the
          # legend will also become more translucent. Unfortunately this is a
          # bit tricky because adding a manual legend here would override the
          # best fit and 45 degree line legend components. In particular, the
          # best fit is plotted in draw because it depends on y and y_pred.
          self.ax.legend(loc='best', frameon=True)