title: How to start a new activity from a non activity class in Android kotlin?
body: <p>I've been trying to pass the context but it just doesn't work
  so I declare it first using</p>
  
  <pre><code>var mContext: Context? = null
  </code></pre>
  
  <p>then in one of my function (from non activity class) I call it</p>
  
  <pre><code>val intent= Intent(mContext, NotificationActivity::class.java)
  mContext?.startActivity(intent)
  </code></pre>
  
  <p>It doesn't show error in coding but when I run this app, it just doesn't work</p>
  
  <p>NotificationActivity is the class that I want to call</p>