title: How to use onCall with aws-sdk-mock?
body: <p>I would like let the mock method enable different responses for consecutive calls to the same method.</p>
  
  <p>I found that Sinon has onCall, it allowed I can stub method like below,</p>
  
  <pre><code>        let stubCall = sandbox.stub(Math, 'random');
          stubCall.onCall(0).returns(Promise.resolve(0));
          stubCall.onCall(1).returns(Promise.resolve(-1));
  </code></pre>
  
  <p>but I don't know how to let this work on AWS mock framework like this.</p>
  
  <pre><code>        AWS.mock('CloudFormation', 'describeStacks', Promise.resolve(stackResponse));
  </code></pre>
  
  <p>I tried </p>
  
  <pre><code>AWS.mock('CloudFormation', 'describeStacks', Promise.resolve(stackResponse)).onCall(0).returns(Promise.resolve(res));
  </code></pre>
  
  <p>and </p>
  
  <pre><code>let mockCall = AWS.mock('CloudFormation', 'describeStacks', Promise.resolve(res));
  mockCall.onCall(0).returns(Promise.resolve(res));
  </code></pre>
  
  <p>both of them didn't work.</p>
  
  <p>I found people <a href="https://github.com/dwyl/aws-sdk-mock/issues/93" rel="nofollow noreferrer">discuss this issue</a> , mentioned since this aws-mock use sinon, it should able to use onCall. Is anyone use it successfully? </p>
  
  <p>Since I use promise, I don't know what else I can do to return the different response for the same method has been called several times.</p>