[
  {
    "type": "mapgen",
    "update_mapgen_id": "mx_city_trap",
    "object": { "place_nested": [ { "chunks": [ "3x3_city_trap" ], "x": [ 4, 17 ], "y": [ 4, 17 ] } ] }
  },
  {
    "type": "mapgen",
    "nested_mapgen_id": "3x3_city_trap",
    "object": {
      "mapgensize": [ 3, 3 ],
      "rows": [
        "///",
        "/O/",
        "///"
      ],
      "remove_vehicles": [ { "x": [ 0, 2 ], "y": [ 0, 2 ] } ],
      "furniture": { "/": "f_clear", "O": "f_clear" },
      "traps": { "/": "tr_blade", "O": "tr_engine" },
      "monster": { "O": { "monster": "mon_turret_speaker", "chance": 100 } }
    }
  }
]
