def METHOD_NAME(instance):
    op = instance.firrtl_op
    instance_name = str(instance.name)
    # s = "inst {} of {}\n".format(instance_name, str(instance.__class__.__name__))
    outputs = instance.interface.outputs()
    assert len(outputs) == 1, "FIRRTL primitive should only have one output"
    port = outputs[0]
    args = []
    for name, port in instance.interface.ports.items():
        if port.is_input():
            value = port.value()
            if not value:
                print('Warning (firrtl): input', str(port), 'not connected to an output')
                value = port
            args.append(get_name(value))
    return "{} <= {}({})\n".format(get_name(port), instance.firrtl_op, ", ".join(args))