Null not correctly reprsented in JSON output

[dfmorrison]

If, in nodeGame, I do

node.game.memory.add({player: node.player.id, stage: node.player.stage, data: { "foo": null }}); node.game.memory.save("data.json");

I get

​{ "player": "681934395222262", "stage": { "stage": 2, "step": 1, "round": 1 }, "data": { "foo": "!?_null" }, "timestamp": 1516569132070 }​

where instead I would have expected something like

​{ "player": "681934395222262", "stage": { "stage": 2, "step": 1, "round": 1 }, "data": { "foo": null }, "timestamp": 1516569132070 }​