WP_Customize_Manager::get_allowed_urls PHP Method

    public function get_allowed_urls()
    {
        $allowed_urls = array(home_url('/'));
        if (is_ssl() && !$this->is_cross_domain()) {
            $allowed_urls[] = home_url('/', 'https');
        }
        /**
         * Filters the list of URLs allowed to be clicked and followed in the Customizer preview.
         *
         * @since 3.4.0
         *
         * @param array $allowed_urls An array of allowed URLs.
         */
        $allowed_urls = array_unique(apply_filters('customize_allowed_urls', $allowed_urls));
        return $allowed_urls;
    }

 /**
  * Test WP_Customize_Manager::get_allowed_urls().
  *
  * @ticket 30937
  * @covers WP_Customize_Manager::get_allowed_urls()
  */
 function test_get_allowed_urls()
 {
     $wp_customize = new WP_Customize_Manager();
     $this->assertFalse(is_ssl());
     $this->assertFalse($wp_customize->is_cross_domain());
     $allowed = $wp_customize->get_allowed_urls();
     $this->assertEquals($allowed, array(home_url('/', 'http')));
     add_filter('customize_allowed_urls', array($this, 'filter_customize_allowed_urls'));
     $allowed = $wp_customize->get_allowed_urls();
     $this->assertEqualSets($allowed, array('http://headless.example.com/', home_url('/', 'http')));
 }