added unit testing, and started implementing unit tests...phew

node_modules/async/internal/slice.js

@@ -0,0 +1,16 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+exports.default = slice;
+function slice(arrayLike, start) {
+    start = start | 0;
+    var newLen = Math.max(arrayLike.length - start, 0);
+    var newArr = Array(newLen);
+    for (var idx = 0; idx < newLen; idx++) {
+        newArr[idx] = arrayLike[start + idx];
+    }
+    return newArr;
+}
+module.exports = exports["default"];