Apple_Exporter\Builders\Component_Layouts::register_layout PHP Method

    public function register_layout($name, $spec)
    {
        // Only register once, layouts have unique names.
        if ($this->layout_exists($name)) {
            return;
        }
        $this->layouts[$name] = $spec;
    }

 public function testRegisterLayout()
 {
     $layouts = new Component_Layouts($this->content, $this->settings);
     $layouts->register_layout('l1', 'val1');
     $layouts->register_layout('l2', 'val2');
     $result = $layouts->to_array();
     $this->assertEquals(2, count($result));
     $this->assertEquals('val1', $result['l1']);
     $this->assertEquals('val2', $result['l2']);
 }