How do you create two grid columns like the Entry Edit page within a plugin? I have a plugin where I'd like my CP tab to output two columns just like the entry page.  On the left, would be the body and then there would be a nice dividing gap and then on the right there would be a aside column.

I've tried to copy the way that the Entry Edit page works but I must be missing something.

Extending _layouts/cp wraps everything on the page with the following three divs which don't seem to get output at all on the Entry Edit page:

&lt;div class="grid"&gt;
    &lt;div class="item"&gt;
        &lt;div class="pane"&gt;
             ...
        &lt;/div&gt;
    &lt;/div&gt;
&lt;/div&gt;


How does the entry page get rid of these divs?  I'm not seeing anything obvious in the templates.

EDIT To be clear, I can create the layout that I want, except for the fact that the layout I want gets wrapped in the above code and makes the gutter disappear and messes up the padding around the two columns on the page.  If I extend the {% extends '_layouts/cp' %} and remove those three divs above, just like the Edit and Entry page seems to do somehow, the page displays just as I want it to.  

What I can't figure out is how the Entry page is getting rid of those three divs. It uses {% extends '_layouts/cp' %} and those divs do not appear on the Edit an Entry page.
templates/layouts/_cp.html has 

&lt;div class="grid"&gt;
  &lt;div class="item"&gt;
    &lt;div class="pane"&gt;


nested inside the {% block main %} (line  207) and templates/entries/_edit.html is overriding that block main, so those grid,item,pane divs get overridden too.