DB » Multiple connections CI3 ?

$DB1 = $this->load->database('group_one', TRUE);
$DB2 = $this->load->database('group_two', TRUE);

I will detail my nonfunctional code?

» File Setup » database.php

$active_group = 'dbone';
$query_builder = TRUE;

$db['dbone'] = array(
'dsn' => '',
'hostname' => '000.000....',
'username' => '',
'password' => '',
'database' => '',
'dbdriver' => 'mysqli',
'dbprefix' => '',
'pconnect' => FALSE,
'db_debug' => (ENVIRONMENT !== 'production'),
'cache_on' => FALSE,
'cachedir' => '',
'char_set' => 'utf8',
'dbcollat' => 'utf8_general_ci',
'swap_pre' => '',
'encrypt' => FALSE,
'compress' => FALSE,
'stricton' => FALSE,
'failover' => array(),
'save_queries' => TRUE
);

//$active_group = 'dbtwo';
//$query_builder = TRUE;

$db['dbtwo'] = array(
'dsn' => '',
'hostname' => '000.000...',
'username' => '',
'password' => '',
'database' => '',
'dbdriver' => 'mysqli',
'dbprefix' => '',
'pconnect' => FALSE,
'db_debug' => (ENVIRONMENT !== 'production'),
'cache_on' => FALSE,
'cachedir' => '',
'char_set' => 'utf8',
'dbcollat' => 'utf8_general_ci',
'swap_pre' => '',
'encrypt' => FALSE,
'compress' => FALSE,
'stricton' => FALSE,
'failover' => array(),
'save_queries' => TRUE
);

File_model.php


<?php defined('BASEPATH') OR exit('No direct script access allowed');

class File_model extends CI_Model {

public function insert() {
$dbs = $this->load->database('screens', TRUE);
$email = 'myemail';
$this->db->insert('ws_user_on', $$email);
}
}

I can not see error? And simply does not work?