+sizeof(struct json_object_iterator)/sizeof(void *)=1
+key: string_of_digits
+pre change: "123"
+post change: "switched"
+key: regular_number
+pre change: 222
+post change: "switched"
+key: decimal_number
+pre change: 99.55
+post change: "switched"
+key: boolean_true
+pre change: true
+post change: "switched"
+key: boolean_false
+pre change: false
+post change: "switched"
+key: big_number
+pre change: 2147483649
+post change: "switched"
+key: a_null
+pre change: null
+post change: "switched"
+key: an_object
+pre change: { "foo": "bar" }
+post change: { "foo": "change foo", "newkey": "new value" }