Xorshift prototype next function this this 11 this this this this this

Xorshift.prototype.next = function(){
  t = this.x ^ (this.x << 11);
  this.x = this.y; this.y = this.z; this.z = this.w;
  return this.w = this.w ^ (this.w >> 19) ^ t ^ (t >> 8);
}