title: Unsetting a variable in Velocity
body: <p>Is it possible to set a Velocity reference to 'null' or 'undefined'?</p>
  
  <p>The <a href="http://velocity.apache.org/engine/devel/vtl-reference-guide.html" rel="noreferrer">Velocity template language reference</a> says</p>
  
  <blockquote>
    <p><code>#set</code> - Establishes the value of a reference
    Format: </p>
    
    <p><code># [ { ] set [ } ] ( $ref = [ ", ' ]arg[ ", ' ] )</code></p>
    
    <p>Usage: </p>
    
    <p><code>$ref</code> - The LHS of the assignment must be a variable reference or a property reference.</p>
    
    <p><code>arg</code> - The RHS of the assignment, arg is parsed if enclosed in double quotes, and not
    parsed if enclosed in single quotes. <em>If the RHS evaluates to null, it is not assigned
    to the LHS.</em> (emphasis mine)</p>
  </blockquote>
  
  <p>I cannot find an equivalent <code>#unset</code> macro.</p>