Images CRUD (GroceryCRUD)

Hello,

I am trying to understand the code of image gallery:

http://www.grocerycrud.com/image-crud

I do not understand why:  new image_CRUD();  is being define?  Where does it comes from?

controllers/images_examples.php

PHP Code:

    function example1()
    {
        $image_crud = new image_CRUD();
        
        $image_crud->set_primary_key_field('id');
        $image_crud->set_url_field('url');
        $image_crud->set_table('example_1')
            ->set_image_path('assets/uploads');
            
        $output = $image_crud->render();
        
        $this->_example_output($output);
    } 


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