code: function arrCopy(arr, offset) {
  	    offset = offset || 0;
  	    var len = Math.max(0, arr.length - offset);
  	    var newArr = new Array(len);
  	    for (var ii = 0; ii < len; ii++) {
  	      newArr[ii] = arr[ii + offset];
  	    }
  	    return newArr;
  	  }
docs: http://jsperf.com/copy-array-inline