Carbon_Fields\Widget\Widget::verify_unique_field_name PHP Method

    public function verify_unique_field_name($name)
    {
        static $registered_field_names = array();
        if (in_array($name, $registered_field_names)) {
            Incorrect_Syntax_Exception::raise('Field name "' . $name . '" already registered');
        }
        $registered_field_names[] = $name;
    }