JSON and Uint8Array

Problem with var x=JSON.parse(JSON.stringify(Obj));
When Obj contains an Uint8Array(N). x is undefined/

function A(){
 this.A=1;
 this.B= new Uint8Array(16);
 this.s= new Uint8Array(16);
}

A.prototype.setup=function(){
 var i;
 for(i=0;i<16;i++)this.B[i]=i;
};

function B(){
 this.B= 2; // new Uint8Array(16);
 this.s= 2; //new Uint8Array(16);
 this.A=1;
}


var a=new A();
a.setup();
console.log(a);
var e=JSON.stringify(a);
console.log(e);
var f=JSON.parse(e);
console.log("f= ",f);

console.log(" ");
var b=new B();
console.log(b);
var e1=JSON.stringify(b);
console.log(e1);
var f1=JSON.parse(e1);
console.log("f1= ",f1);

The output:

>echo(0);
{ "A": 1,
  "B": new Uint8Array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]),
  "s": new Uint8Array(16)
 }
{"A":1,"B":new Uint8Array([0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]),"s":new Uint8Array(16)}
f=  undefined
 
{ "B": 2, "s": 2, "A": 1 }
{"B":2,"s":2,"A":1}
f1=  { "B": 2, "s": 2, "A": 1 }