autocde2.0/app/ModelFilters/ContainerFilter.php

<?php 

namespace App\ModelFilters;

use EloquentFilter\ModelFilter;

class ContainerFilter extends ModelFilter
{
    /**
    * Related Models that have ModelFilters as well as the method on the ModelFilter
    * As [relationMethod => [input_key1, input_key2]].
    *
    * @var array
    */
    public $relations = [];

    public function library($id)
    {
        return $this->where("library_id", $id);
    }
}