Model return Undefined variable: table

I get ErrorException
Undefined variable: table
APPPATH/Models/OptionsModel.php at line 22

Code:

22: $option_value = $table->find($item);

app/Models/OptionsModel.php

Code:

<?php namespace App\Models;

use CodeIgniter\Model;

class OptionsModel extends Model
{
    protected $DBGroup = 'default';
    protected $table = 'options';
    protected $primaryKey = 'option_name';
    protected $returnType = 'array';

    public function get_options($item, $display = 0)
    {
        $option_value = $table->find($item);

        if (empty($option_value)) {
            if (!$display) {
                return $option_value;
            } else {
                echo $option_value;
            }
        }
    }

}

Any help will be appreciated. Thanks!