def METHOD_NAME(value):
    """
    Throws an error if the specified path is a link. os.islink returns
    True for sym links.  For files, we also look at the number of links in
    os.stat() to determine if it's a hard link.
    """
    if os.path.islink(value) or \
            (os.path.isfile(value) and os.stat(value).st_nlink > 1):
        raise ArgumentTypeError("{} cannot be a link.".format(value))