code: def set_variations(self, variations):
          
          if variations is None:
              variations = ffi.NULL
          else:
              variations = _encode_string(variations)
          cairo.cairo_font_options_set_variations(self._pointer, variations)
          self._check_status()
docs: Sets the OpenType font variations for the font options object.
  
          Font variations are specified as a string with a format that is similar
          to the CSS font-variation-settings. The string contains a
          comma-separated list of axis assignments, which each assignment
          consists of a 4-character axis name and a value, separated by
          whitespace and optional equals sign.
  
          :param variations: the new font variations, or ``None``.
  
          *New in cairo 1.16.*
  
          *New in cairocffi 0.9.*