code: function() {
  			var mag = this.x * this.x + this.y * this.y;
  			if (mag > 0) {
  				mag = 1.0 / Math.sqrt(mag);
  				this.x *= mag;
  				this.y *= mag;
  			}
  			return this;
  		}
docs: Normalizes the vector so that its magnitude = 1
  
  @return itself