nodes: 0, module; 1, function_definition; 2, function_name:sortable_sortkey_title; 3, parameters; 4, block; 5, identifier:instance; 6, expression_statement; 7, expression_statement; 8, if_statement; 9, expression_statement; 10, if_statement; 11, return_statement; 12, comment:"""Returns a sortable title as a mxin of sortkey + lowercase sortable_title
      """; 13, assignment; 14, call; 15, block; 16, assignment; 17, comparison_operator:sort_key is None; 18, block; 19, call; 20, identifier:title; 21, call; 22, identifier:safe_callable; 23, argument_list; 24, expression_statement; 25, identifier:sort_key; 26, call; 27, identifier:sort_key; 28, None; 29, expression_statement; 30, attribute; 31, argument_list; 32, identifier:sortable_title; 33, argument_list; 34, identifier:title; 35, assignment; 36, attribute; 37, argument_list; 38, assignment; 39, string:"{:010.3f}{}"; 40, identifier:format; 41, identifier:sort_key; 42, identifier:title; 43, identifier:instance; 44, identifier:title; 45, call; 46, identifier:instance; 47, identifier:getSortKey; 48, identifier:sort_key; 49, integer:999999; 50, identifier:title; 51, argument_list
code: def sortable_sortkey_title(instance):
      """Returns a sortable title as a mxin of sortkey + lowercase sortable_title
      """
      title = sortable_title(instance)
      if safe_callable(title):
          title = title()
  
      sort_key = instance.getSortKey()
      if sort_key is None:
          sort_key = 999999
  
      return "{:010.3f}{}".format(sort_key, title)