title: Line on the right in Intellij Idea code editor
body: <p>What is that line on the right in Intellij Idea code editor?</p>
  
  <p>Here you can see the line:</p>
  
  <p><a href="https://i.stack.imgur.com/ekbKu.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ekbKu.png" alt="enter image description here"></a></p>