public SlideUp(HtmlElement el, BlindOptions options)
     : base(el, options)
 {
 }
 public BlindDown(HtmlElement el, BlindOptions options)
     : base(el, options)
 {
 }
 public SlideUp(JsString id_of_element, BlindOptions options)
     : base(id_of_element, options)
 {
 }
 public BlindDown(JsString id_of_element, BlindOptions options)
     : base(id_of_element, options)
 {
 }