text: if(typeof define!=='function'){var define=require('amdefine')(module);}
  
  define(['onion/utils/extend'], function(extend){
  
    var chainPrototype = function (child, parent) {
      function ctor() {
        this.constructor = child
      }
      ctor.prototype = parent.prototype
      child.prototype = new ctor()
    }
  
    return function (child, parent) {
      extend(child, parent)
      chainPrototype(child, parent)
    }
  })
  