usesuper::INodeTrait;pubtypeBoxDynText<'a>=Box<dyn ITextTrait +'a>;pubtraitITextTrait: INodeTrait {// remove the ele
fnremove(self: Box<Self>);// append text at the end
fnappend_text(&mutself, content:&str);// prepend text at the start
fnprepend_text(&mutself, content:&str);}