{ str: "pony" }, { str: "my" }, { str: "little" }, { str: "" } ],
        [ 0, 2, 4, 6 ]);

    keypath('arr.length',
        [ {arr: [0, 0, 0, 0]}, {arr: [{}, 0, "hei", "length", Infinity, []]}, {arr: [10, 10]}, { arr: []} ],
        [ 0, 2, 4, 6 ]);

    keypath('length',
        [ [10, 10], "123", { length: 20 } ],
        [ 2, 3, 20 ]);

    keypath('',
        [ ["bags"], "bean", 10 ],
        [ 10, "bean", ["bags"] ],
        "'' uses value as key");

    keypath([''],
        [ ["bags"], "bean", 10 ]