title: Remove last line from a StringBuilder without knowing the number of characters
body: <p>I want to know if there exists a simple method for removing the last line from a StringBuilder object without knowing the number of characters in the last line.</p>
  
  <p>Example:</p>
  
  <blockquote>
    <p>Hello, how are you?<br>
    Fine thanks!<br>
    Ok, Perfect...  </p>
  </blockquote>
  
  <p>I want to remove "Ok, Perfect..."</p>