code: function getOwnPropertyDescriptor(state, prop) {
      const owner = source(state)
      const desc = Reflect.getOwnPropertyDescriptor(owner, prop)
      if (desc) {
          desc.writable = true
          desc.configurable = !Array.isArray(owner) || prop !== "length"
      }
      return desc
  }
docs: Note: We never coerce `desc.value` into an Immer draft, because we can't make the same guarantee in ES5 mode.