title: angular 2 how to import custom function to component and service
body: <p>I have a function like this</p>
  
  <p><strong>myHelperNumber.js</strong></p>
  
  <pre><code>function myLittleBoy(){
    console.log('I see you)
  }
  </code></pre>
  
  <p>How to use this function in User.js component or userSevicer.js service?</p>