title: How to mock navigation.useragent
body: <p>I am tesing a react project using jest and react-testing-library.</p>
  
  <p>The project has different code for navigator.useragent contains android / mobile / blackberry .</p>
  
  <p>To test the code, I have to mock the navigation.useragent.</p>
  
  <p>How I can achieve the mocking.</p>