title: Receiving undefined method error when monkey patching
body: <p>I'm getting the the error </p>
  
  <pre class="lang-none prettyprint-override"><code>`&lt;main&gt;': undefined method `my_uniq' for Array:Class (NoMethodError)
  </code></pre>
  
  <p>when running the following code</p>
  
  <pre><code>class Array
    def my_uniq(array)
      new_arr = []
  
      array.each do |i|
        if !new_arr.include?(i)
          new_arr &lt;&lt; i
        end
      end
  
      return new_arr
    end
  end
  
  test = Array.my_uniq([1,2,3])
  </code></pre>
  
  <p>Any help fixing this would be much appreciated.</p>