expect_equal(to_json(list(1), auto_unbox=TRUE), "[1]");
expect_equal(to_json(list(I(1)), auto_unbox=TRUE), "[[1]]");
expect_equal(to_json(I(list(1)), auto_unbox=TRUE), "[1]");

expect_equal(to_json(list(x=1)), "{\"x\":[1]}");
expect_equal(to_json(list(x=1), auto_unbox=TRUE), "{\"x\":1}");
expect_equal(to_json(list(x=I(1)), auto_unbox=TRUE), "{\"x\":[1]}");

expect_equal(to_json(list(x=I(list(1))), auto_unbox=TRUE), "{\"x\":[1]}");
expect_equal(to_json(list(x=list(I(1))), auto_unbox=TRUE), "{\"x\":[[1]]}");