dist/yodata-context.js
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;
	  }
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;
	  }
http://jsperf.com/copy-array-inline