code: function shallowEqual(a, b) {
    let ret = true
  
    for (const key in a) {
      if (a[key] !== b[key]) {
        ret = false
        break
      }
    }
  
    if (ret) {
      for (const key in b) {
        if (!(key in a)) {
          ret = false
          break
        }
      }
    }
  
    return ret
  }
docs: --- locals -------------------------------------------------------