code: def save(self, annot=None, output_path=None):
          
  
          if annot is not None:
              self.fig.suptitle(annot, backgroundcolor='black', color='g')
  
          if output_path is not None:
              output_path = output_path.replace(' ', '_')
              # TODO improve bbox calculations to include ONLY the axes from collage
              # and nothing else
              self.fig.savefig(output_path + '.png', bbox_inches='tight', dpi=200,
                               bbox_extra_artists=self.flat_grid)
docs: Saves the collage to disk as an image.
  
          Parameters
          -----------
  
          annot : str
              text to annotate the figure with a super title
  
          output_path : str
              path to save the figure to.
              Note: any spaces in the filename will be replace with ``_``