Carbon_Fields\Container\Theme_Options_Container::verify_unique_page PHP Method

    public function verify_unique_page()
    {
        $file = $this->settings['file'];
        $parent = $this->settings['parent'];
        // Register top level page
        if (!$parent) {
            if (isset(self::$registered_pages[$file])) {
                Incorrect_Syntax_Exception::raise('Page "' . $file . '" already registered');
            }
            self::$registered_pages[$file] = array();
            return;
        }
        // Register sub-page
        if (!isset(self::$registered_pages[$parent])) {
            self::$registered_pages[$parent] = array($file);
        } elseif (in_array($file, self::$registered_pages[$parent])) {
            Incorrect_Syntax_Exception::raise('Page "' . $file . '" with parent "' . $parent . '" is already registered. Please set a different file name using setup()');
        } else {
            self::$registered_pages[$parent][] = $file;
        }
    }