presto-main/src/main/java/io/prestosql/server/security/PasswordAuthenticatorManager.java/PasswordAuthenticatorManager/addPasswordAuthenticatorFactory
class PasswordAuthenticatorManager:    public void addPasswordAuthenticatorFactory(PasswordAuthenticatorFactory factory)
    {
        checkArgument(factories.putIfAbsent(factory.getName(), factory) == null,
                "Password authenticator '%s' is already registered", factory.getName());
    }