title: How to make pre-selected checkbox in django?
body: <p>My form has <code>CheckboxSelectMultiple</code> widget receiving user's preferences.<br/>
  I want to show a pre-checked preference to user. <br />
  I know there is one way to pre-check widget in the template. <br />
  But I want to know a way to pre-check in the <em>view</em> individually.
  How can I do that?</p>