每个权限集中都有三个访问位：读、写和执行。
Within each set, you have three access bits: read, write, and execute.
“access”参数表示访问的类型(读、写或执行)。
The "access" parameter denotes the type of access (read, write, or execute).
Realm写操作：目前所有Realm实现都支持“读”操作来获取验证和授权数据以执行登录和访问控制。
Realm Write operations: Currently all Realm implementations support 'read' operations for acquiring authentication and authorization data to perform logins and access control.
应用推荐