driver-legacy/src/main/com/mongodb/DB.java
@Deprecated
    public WriteResult addUser(final String userName, final char[] password) {
        return addUser(userName, password, false);
    }
@Deprecated
    public WriteResult addUser(final String userName, final char[] password) {
        return addUser(userName, password, false);
    }
Adds or updates a user for this database

<p>Never create or modify users over an insecure network without the use of TLS.</p>
@param userName the user name
@param password the password
@return the result of executing this operation
@throws MongoException if the operation failed
@mongodb.driver.manual administration/security-access-control/  Access Control
@mongodb.driver.manual reference/command/createUser createUser
@mongodb.driver.manual reference/command/updateUser updateUser
@deprecated Use {@code DB.command} to call either the createUser or updateUser command