title: underscore how to use omit
body: <p>How does underscore's omit work. I was expecting to remove properties with key 1 and 2 below. but it is not.</p>
  
  <p><a href="http://jsfiddle.net/FMaDq/1/" rel="noreferrer">http://jsfiddle.net/FMaDq/1/</a></p>
  
  <pre><code>var test = {
      1: [],
      2: [],
      3: [],
      4: []
  }
  
  var out = _.omit(test, [1,2])
  var out2 = _.omit(test, 1,2)
  console.log(out)
  console.log(out2)
  
  Object {1: Array[0], 2: Array[0], 3: Array[0], 4: Array[0]}
  Object {1: Array[0], 2: Array[0], 3: Array[0], 4: Array[0]}
  </code></pre>