title: Game Screeps - Using the lodash module
body: <p>I'm playing Screeps (<a href="http://screeps.com" rel="nofollow">http://screeps.com</a>) and I'm trying to use the lodash module for filtering my harvesters from the rest of the creeps. The code below should work but when I run it I get a <code>ReferenceError: _ is not defined at &lt;main&gt;:6:18</code>. Any idea of what's wrong?</p>
  
  <pre><code>var harvesters = _.filter(Game.creeps, {memory: 'harvester'});
  if(_.size(harvesters) &lt; 3 &amp;&amp; Memory.creep_queue.length===0) {
       Memory.creep_queue.push('harvester') 
  }
  </code></pre>