def resolve___call__(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))

        Resolve the named tuple constructor, aka the class's __call__ method.
        
numba/core/typing/collections.py