title: Mocking Request Header module using Jest
body: <pre><code>function createRequest(method) {
       const init = {
           method,
           headers: new Headers({.....}),
       };
  
      return new Request(url, init); }
  </code></pre>
  
  <p>I am using Request headers (with Fetch) in the above code (<a href="https://davidwalsh.name/fetch" rel="noreferrer">https://davidwalsh.name/fetch</a> )</p>
  
  <p>However while writing unit test cases using Jest, it gives me this error:   ReferenceError: Headers is not defined</p>
  
  <p>DO I need to mock even these standard modules? How should I import Headers in unit test cases</p>