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

node_modules/@sinonjs/samsam/lib/create-set.js

@@ -0,0 +1,27 @@
+"use strict";
+
+var typeOf = require("@sinonjs/commons").typeOf;
+
+// This helper makes it convenient to create Set instances from a
+// collection, an overcomes the shortcoming that IE11 doesn't support
+// collection arguments
+//
+// See: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set
+function createSet(array) {
+    if (arguments.length > 0 && !Array.isArray(array)) {
+        throw new TypeError(
+            "createSet can be called with either no arguments or an Array"
+        );
+    }
+
+    var items = typeOf(array) === "array" ? array : [];
+    var set = new Set();
+
+    items.forEach(function(item) {
+        set.add(item);
+    });
+
+    return set;
+}
+
+module.exports = createSet;