title: Is it possible to undefine a variable in freemarker?
body: <p>In the freemarker template language, I can test whether a variable exists by using constructs like <code>variable?exists</code> or <code>variable??</code>. I can also cause a previously non-existent variable to exist by assigning to it, e.g., <code>&lt;#assign variable = "hi" /&gt;</code>. But how can I cause a previously existing variable to no longer exist?</p>
  
  <p>I have some other dude's freemarker template, with logic at various points that tests for the (non-)existence of certain variables. In my use case, it would be simplest if I could have a variable that exists at one point, then becomes undefined when including his template, then gets assigned to again later on. The alternative is to restructure things more significantly.</p>