docs: def get_config_paths(config_name):  # pragma: no test
      """
      Return a list of config files paths to try in order, given config file
      name and possibly a user-specified path.
  
      For Windows platforms, there are several paths that can be tried to
      retrieve the netrc file. There is, however, no "standard way" of doing
      things.
  
      A brief recap of the situation (all file paths are written in Unix
      convention):
  
      1. By default, Windows does not define a $HOME path. However, some
      people might define one manually, and many command-line tools imported
      from Unix will search the $HOME environment variable first. This
      includes MSYSGit tools (bash, ssh, ...) and Emacs.
  
      2. Windows defines two 'user paths': $USERPROFILE, and the
      concatenation of the two variables $HOMEDRIVE and $HOMEPATH. Both of
      these paths point by default to the same location, e.g.
      C:\\Users\\Username
  
      3. $USERPROFILE cannot be changed, however $HOMEDRIVE and $HOMEPATH
      can be changed. They are originally intended to be the equivalent of
      the $HOME path, but there are many known issues with them
  
      4. As for the name of the file itself, most of the tools ported from
      Unix will use the standard '.dotfile' scheme, but some of these will
      instead use "_dotfile". Of the latter, the two notable exceptions are
      vim, which will first try '_vimrc' before '.vimrc' (but it will try
      both) and git, which will require the user to name its netrc file
      '_netrc'.
  
      Relevant links :
      http://markmail.org/message/i33ldu4xl5aterrr
      http://markmail.org/message/wbzs4gmtvkbewgxi
      http://stackoverflow.com/questions/6031214/
  
      Because the whole thing is a mess, I suggest we tried various sensible
      defaults until we succeed or have depleted all possibilities.
      """
  
      if platform.system() != 'Windows':
          return [None]
  
      # Now, we only treat the case of Windows
      env_vars = [["HOME"],
                  ["HOMEDRIVE", "HOMEPATH"],
                  ["USERPROFILE"],
                  ["SYSTEMDRIVE"]]
  
      env_dirs = []
      for var_list in env_vars:
  
          var_values = [_getenv_or_empty(var) for var in var_list]
  
          directory = ''.join(var_values)
          if not directory:
              logging.debug('Environment var(s) %s not defined, skipping',
                            var_list)
          else:
              env_dirs.append(directory)
  
      additional_dirs = ["C:", ""]
  
      all_dirs = env_dirs + additional_dirs
  
      leading_chars = [".", "_"]
  
      res = [''.join([directory, os.sep, lc, config_name])
             for directory in all_dirs
             for lc in leading_chars]
  
      return res