code: def image_bytes(b, filename=None, inline=1, width='auto', height='auto',
      preserve_aspect_ratio=None):
      
      if preserve_aspect_ratio is None:
          if width != 'auto' and height != 'auto':
              preserve_aspect_ratio = False
          else:
              preserve_aspect_ratio = True
      data = {
          'name': base64.b64encode((filename or 'Unnamed file').encode('utf-8')).decode('ascii'),
          'inline': inline,
          'size': len(b),
          'base64_img': base64.b64encode(b).decode('ascii'),
          'width': width,
          'height': height,
          'preserve_aspect_ratio': int(preserve_aspect_ratio),
          }
      # IMAGE_CODE is a string because bytes doesn't support formatting
      return IMAGE_CODE.format(**data).encode('ascii')
docs: Return a bytes string that displays image given by bytes b in the terminal
  
      If filename=None, the filename defaults to "Unnamed file"
  
      width and height are strings, following the format
  
          N: N character cells.
  
          Npx: N pixels.
  
          N%: N percent of the session's width or height.
  
          'auto': The image's inherent size will be used to determine an appropriate
                  dimension.
  
      preserve_aspect_ratio sets whether the aspect ratio of the image is
      preserved. The default (None) is True unless both width and height are
      set.
  
      See https://www.iterm2.com/documentation-images.html