def METHOD_NAME(self, classty):
    """
    Resolve the named tuple constructor, aka the class's __call__ method.
    """
    instance_class = classty.instance_class
    pysig = utils.pysignature(instance_class)
    def typer(*args, **kws):
        # Fold keyword args
        try:
            bound = pysig.bind(*args, **kws)
        except TypeError as e:
            msg = "In '%s': %s" % (instance_class, e)
            e.args = (msg,)
            raise
        assert not bound.kwargs
        return types.BaseTuple.from_types(bound.args, instance_class)
    # Override the typer's pysig to match the namedtuple constructor's
    typer.pysig = pysig
    return types.Function(make_callable_template(self.key, typer))