undefined method CI_Model::get()

Pages controller
[code]
<?php if(!defined('BASEPATH')) exit ('No direct script access allowed');

class Pages extends MX_Controller{

    public function __construct() {
        parent::__construct();
        $this->load->model('pages_model');
        $this->load->library('form_validation');
    }

    function manage(){
        $data['pages'] = $this->pages_model->get();

        $data['view_file'] = "manage";
        $this->load->module('templates');
        $this->templates->admin($data);
    }

    public function edit($id = NULL){
        if($id){
            $data['page'] = $this->pages_model->get($id);
            count($data['page']) || $data['errors'][] = 'User could not be found';
        } else {
            $data['page'] = $this->pages_model->get_new();
        }

        //pages for dropdown
        $data['pages_no_parents'] = $this->pages_model->get_no_parents();
        dump($data['pages_no_parents']);

        //$id == NULL || $data['page'] = $this->pages_model->get($id);
        $rules = $this->pages_model->rules;
        $this->form_validation->set_rules($rules);
        if($this->form_validation->run() == TRUE){
            $data = $this->pages_model->array_from_post(array('title', 'slug', 'body'));
            $this->pages_model->save($data, $id);
            redirect('pages/manage');
        }

        $data['view_file'] = "edit";
        $this->load->module('templates');
        $this->templates->admin($data);
    }

    public function _unique_slug($str){
        $id = $this->uri->segment(3);
        $this->db->where('slug', $this->input->post('slug'));
        !$id || $this->db->where('id !=', $id);
        $page = $this->pages_model->get();

        if(count($page)){
            $this->form_validation->set_message('_unique_slug', '%s should be unique');
            return FALSE;
        }

        return TRUE;
    }

    public function delete($id){
        $this->pages_model->delete($id);
        redirect('pages/manage');
    }

    function get($order_by){
        $this->load->model('pages_model');
        $query = $this->pages_model->get($order_by);
        return $query;
    }

    function get_with_limit($limit, $offset, $order_by) {
        $this->load->model('pages_model');
        $query = $this->pages_model->get_with_limit($limit, $offset, $order_by);
        return $query;
    }

    function get_where($id){
        $this->load->model('pages_model');
        $query = $this->pages_model->get_where($id);
        return $query;
    }

    function get_where_custom($col, $value) {
        $this->load->model('pages_model');
        $query = $this->pages_model->get_where_custom($col, $value);
        return $query;
    }

    function _insert($data){
        $this->load->model('pages_model');
        $this->pages_model->_insert($data);
    }

    function _update($id, $data){
        $this->load->model('pages_model');
        $this->pages_model->_update($id, $data);
    }

    function _delete($id){
        $this->load->model('pages_model');
        $this->pages_model->_delete($id);
    }

    function count_where($column, $value) {
        $this->load->model('pages_model');
        $count = $this->pages_model->count_where($column, $value);
        return $count;
    }

    function get_max() {
        $this->load->model('pages_model');
        $max_id = $this->pages_model->get_max();
        return $max_id;
    }

    function _custom_query($mysql_query) {
        $this->load->model('pages_model');
        $query = $this->pages_model->_custom_query($mysql_query);
        return $query;
    }
}
[/code]

and this is my pages_model

[code]
<?php if(!defined('BASEPATH')) exit ('No direct script access allowed');

class Pages_model extends CI_Model {

    protected $_table_name = "pages";
    protected $_primary_key = "id";
    protected $_primary_filter = "intval";
    protected $_order_by = "order";
    public $rules = array(
        'parent_id' => array(
            'field' => 'parent_id',
            'label' => 'Parnet',
            'rules' => 'trim|intval'
        ),

        'slug' => array(
            'field' => 'slug',
            'label' => 'Slug',
            'rules' => 'trim|required|max_length[100]|url_title|callback__unique_slug|xss_clean'
        ),

        'order' => array(
            'field' => 'order',
            'label' => 'Order',
            'rules' => 'trim|is_natural|xss_clean'
        ),

        'body' => array(
            'field' => 'body',
            'label' => 'Body',
            'rules' => 'trim|required'
        ),

    );

    protected $_timestamps = "FALSE";

    public function __construct() {
        parent::__construct();
    }


public function get($id = NULL, $single = FALSE){
    if($id != NULL){
        $filter = $this->_primary_filter;
        $id = $filter($id);
        $this->db->where($this->_primary_key, $id);
        $method = 'row';
    } elseif($single == TRUE) {
        $method = 'row';
    } else {
        $method = 'result';
    }

    return $this->db->get($this->_table_name)->$method();
}

public function get_new(){
    $page = new stdClass();
    $page->title = '';
    $page->slug = '';
    $page->body = '';
    $page->parent_id = 0;
    return $page;
}

public function get_by($where, $single = FALSE){
    $this->db->where($where);
    return $this->get(NULL, $single);
}

public function save($data, $id = NULL){
    //Insert
    if($id === NULL){
        !isset($data[$this->_primary_key]) || $data[$this->_primary_key] = NULL;
        $this->db->set($data);
        $this->db->insert($this->_table_name);
        $id = $this->db->insert_id();
    } else {
        //Update
        $filter = $this->_primary_filter;
        $id = $filter($id);
        $this->db->set($data);
        $this->db->where($this->_primary_key, $id);
        $this->db->update($this->_table_name);
    }
    return $id;
}

public function delete($id){
    $filter = $this->_primary_filter;
    $id = $filter($id);

    if(!$id){
        return FALSE;
    }

    $this->db->where($this->_primary_key, $id);
    $this->db->limit(1);
    $this->db->delete($this->_table_name);
}

public function hash($string){
    return hash('sha512', $string . config_item('encryption_key'));
}

public function array_from_post($fields){
    $data = array();
    foreach($fields as $field){
        $data[$field] = $this->input->post($field);
    }

    return $data;
}

public function get_no_parents(){
    //Fetch pages without  parents
    $this->db->select('id', 'title');
    $this->db->where('parent_id', 0);
    //$pages = parent::get();
    $pages = $this->get();
    //echo $this->db->last_query();

    //Return key => value pair array
    $array = array(0 => 'No parent');
    if (count($pages)){
        foreach($pages as $page){
            $array[$page->id] = $page->title;
        }
    }
}

function get_where($id){
$table = $this->get_table();
$this->db->where('id', $id);
$query=$this->db->get($this->_table_name);
return $query;
}

function _insert($data){
$table = $this->get_table();
$this->db->insert($this->_table_name, $data);
}

}
[/code]