def define_token(token):
    """Return the mandatory definition for a token to be used within nstl
       where nstl expects a valid token.

       For example, in order to use an identifier as a method name in a
       nstl type, the definition generated by this function must be written
       for that specific identifier.
    """
    if not isinstance(token, str):
        raise TypeError("{} is not of type {}".format(token, str))
    return "#define NSTL_TOKEN_{} ({})".format(token, " ".join(token))