var stub = sinon.stub();
var opts = { call: function (msg) { console.log(msg); } };
 
// We can control how the sinon.stub() will behave based on how it’s called!
stub.withArgs("Hello").returns("World");
stub.withArgs("Wuz").returns("Zup?");
stub.withArgs("Kapow").throws();
stub.withArgs(opts).yieldsTo("call", ["Howdy"]);
 
stub("Hello"); // "World"
stub(opts); // "Howdy"