title: Eclipse rcp : IFolderLayout, how to keep folder open when all views in it are closed
body: <p>I created a <strong>IFolderLayout</strong> in my perspective, when user close all views in that folder, the folder itself will be closed too. bu t I want it to be remained there.</p>
  
  <pre><code>layout.setEditorAreaVisible(false);
          IFolderLayout functionsViewFolder = layout.createFolder("functionsViewsFolder", IPageLayout.RIGHT, 0.2f, layout.getEditorArea());
          functionsViewFolder.addPlaceholder(FunctionView.ID + ":" + FunctionView.SECONDARY_ID + "*");
  </code></pre>