code: def convert_surfaces(self, parent, alpha=False):
          
          images = list()
          for i in self.tmx.images:
              try:
                  if alpha:
                      images.append(i.convert_alpha(parent))
                  else:
                      images.append(i.convert(parent))
              except AttributeError:
                  images.append(None)
          self.tmx.images = images
docs: Convert all images in the data to match the parent
  
          :param parent: pygame.Surface
          :param alpha: preserve alpha channel or not
          :return: None