title: Sinon error Attempted to wrap function which is already wrapped
body: <p>Though there is a same question here but I could not find answer to my problem so here goes my question: </p>
  
  <p>I am testing my node js app using mocha and chai. I am using sinion to wrap my function. </p>
  
  <pre><code>describe('App Functions', function(){
  
    let mockObj = sinon.stub(testApp, 'getObj', (dbUrl) =&gt; {
       //some stuff
    });
    it('get results',function(done) {
       testApp.someFun
    });
  }
  
  describe('App Errors', function(){
  
    let mockObj = sinon.stub(testApp, 'getObj', (dbUrl) =&gt; {
       //some stuff
    });
    it('throws errors',function(done) {
       testApp.someFun
    });
  }
  </code></pre>
  
  <p>When I try to run this test it gives me error </p>
  
  <pre><code>Attempted to wrap getObj which is already wrapped
  </code></pre>
  
  <p>I also tried putting </p>
  
  <pre><code>beforeEach(function () {
    sandbox = sinon.sandbox.create();
  });
  
  afterEach(function () {
    sandbox.restore();
  });
  </code></pre>
  
  <p>in each describe, but still giving me same error. </p>