code: public B openBrowserAt(String reference) {
          openBrowser(true);
          getConfig().setCustomBrowserUrl(reference);
          return self();
      }
docs: Opens the browser at a custom location. The <tt>reference</tt> parameter can customize the
  url to use to open the browser in the following ways:
  <ul>
  <li>As a <tt>full</tt> URL starting with <em>http://</em> - the url is used as is</li>
  <li>As a relative reference, not starting with <em>/</em> - added to the standard deploy url</li>
  <li>As an absolute reference, starting with <em>/</em> - specify the context of the url</li>
  </ul>
  <p/>
  For instance, consider the scenario when the application is being deployed on port 7080 with
  the <em>my-app</em> context (i.e. <tt>http://localhost:7080/my-app</tt>), the following apply:
  <ul>
  <li><tt>http://localhost:7080/another-app</tt> just use that url as is to open the browser</li>
  <li><tt>?debug#anchor</tt> would use <tt>http://localhost:7080/my-app?debug#anchor</tt></li>
  <li><tt>/another-app/foo</tt> would use <tt>http://localhost:7080/another-app/foo</tt></li>
  </ul>
  Note that this automatically enables the browser if that was not set before so there is no
  need to call {@link #openBrowser(boolean)}.
  
  @param reference a custom url, a relative reference or an absolute reference
  @return this