input: |
  {
    "foo": {
      "bar": {
        "baz": {
          "quux": "4"
        }
      }
    }
  }

output: |
  {
    "foo": {
      "bar": {
        "baz": {
          "quux": "4"
        },
        "qwe": {
          "rty": {
            "aaa": {
              "bbb": 1
            }
          }
        }
      }
    }
  }

test: !!js/function |
  function(jju, input) {
    obj = jju.parse(input)
    obj.foo.bar.qwe = {rty: {aaa: {bbb: 1}}}
    return jju.update(input, obj, {mode:'json'})
  }