5 Configure RBAC:user

1. Syntax
   user user name;
2. Meaning
   Define users who can use the role.
3. Example
   {
   role user_r;
   user root;
   user ynakam;
   ....
   Above means user root and ynakam can use user_r.
4. Constraints
   It can be used only section where role is declared.