AS3 - Embaralha com prototype

// Embaralha Array
Array.prototype.embaralhaArray = function(): *{
   var i,r,a,b
   for (i=0; i<this.length ;i++){
      r=Math.floor(Math.random()*this.length)
      a=this[i]
      this[i]=this[r]
      this[r]=a
   }
  return this
}
var list:Array = ["Bola","Casa","Dado","Elefante"];
trace(list.emabarlhaArray());
trace(list);

//-----------------------------------------------------
// Embaralha String
String.prototype.embaralhaPalavra = function(): *{
   var i,r,a,b
   var bancoTemp:Array=this.split("")
   for (i=0; i<bancoTemp.length ;i++){
      r=Math.floor(Math.random()*bancoTemp.length)
      a=bancoTemp[i]
      bancoTemp[i]=bancoTemp[r]
      bancoTemp[r]=a
   }
  return bancoTemp.join("")
}
var palavraX="abcdef"
trace(palavraX.embaralhaPalavra())