code: func NewCookieStore(keyPairs ...[]byte) *CookieStore {
  	cs := &CookieStore{
  		Codecs: securecookie.CodecsFromPairs(keyPairs...),
  		Options: &Options{
  			Path:   "/",
  			MaxAge: 86400 * 30,
  		},
  	}
  
  	cs.MaxAge(cs.Options.MaxAge)
  	return cs
  }
docs: // CookieStore ----------------------------------------------------------------
  // NewCookieStore returns a new CookieStore.
  //
  // Keys are defined in pairs to allow key rotation, but the common case is
  // to set a single authentication key and optionally an encryption key.
  //
  // The first key in a pair is used for authentication and the second for
  // encryption. The encryption key can be set to nil or omitted in the last
  // pair, but the authentication key is required in all pairs.
  //
  // It is recommended to use an authentication key with 32 or 64 bytes.
  // The encryption key, if set, must be either 16, 24, or 32 bytes to select
  // AES-128, AES-192, or AES-256 modes.