how do I use the node Builder from Scriptacolus to insert html

var html = "<p>This text is <a href=#> good</a></p>";
var newNode = Builder.node('div',{className: 'test'},[html]);
$('placeholder').update(newNode);

var a = Builder.node('div').update("<a href='#'>foo</a>")

var a = Builder.node('div', {'class':'cool'},
         [Builder.node('div', {'class': 'another_div'})]
        );

var a = new Element('div').insert(
          new Element('div', {'class': 'inner_div'}).update("Text in the inner div")
        );