title: Undefined method pluck for array?
body: <p>So I have this data stucture:</p>
  
  <pre><code>+[#&lt;Folder id: 1, name: "mollitia", parent_id: nil, user_id: 1, created_at: "2014-06-27 16:00:59", updated_at: "2014-06-27 16:00:59"&gt;,
  + #&lt;Folder id: 2, name: "porro", parent_id: 1, user_id: 1, created_at: "2014-06-27 16:00:59", updated_at: "2014-06-27 16:00:59"&gt;, 
  + #&lt;Folder id: 3, name: "omnis", parent_id: 2, user_id: 1, created_at: "2014-06-27 16:00:59", updated_at: "2014-06-27 16:00:59"&gt;]
  </code></pre>
  
  <p>which is returned by <code>self.ancestors</code>
  can I pluck its names?</p>
  
  <pre><code>def pwd
      self.ancestors.pluck(:name)
  end
  </code></pre>
  
  <p>The above results in </p>
  
  <pre><code>undefined method `pluck' for #&lt;Array:0x007ff4da780290&gt;
  </code></pre>
  
  <p>Update</p>
  
  <p>Awesome Print of the structure:</p>
  
  <pre><code>[
      [0] #&lt;Folder:0x007fd2946a5f18&gt; {
                  :id =&gt; 3,
                :name =&gt; "blanditiis",
           :parent_id =&gt; 2,
             :user_id =&gt; 1,
          :created_at =&gt; Fri, 27 Jun 2014 18:04:02 UTC +00:00,
          :updated_at =&gt; Fri, 27 Jun 2014 18:04:02 UTC +00:00
      },
      [1] #&lt;Folder:0x007fd2946ad1c8&gt; {
                  :id =&gt; 2,
                :name =&gt; "neque",
           :parent_id =&gt; 1,
             :user_id =&gt; 1,
          :created_at =&gt; Fri, 27 Jun 2014 18:04:02 UTC +00:00,
          :updated_at =&gt; Fri, 27 Jun 2014 18:04:02 UTC +00:00
      },
      [2] #&lt;Folder:0x007fd2946b80c8&gt; {
                  :id =&gt; 1,
                :name =&gt; "ut",
           :parent_id =&gt; nil,
             :user_id =&gt; 1,
          :created_at =&gt; Fri, 27 Jun 2014 18:04:02 UTC +00:00,
          :updated_at =&gt; Fri, 27 Jun 2014 18:04:02 UTC +00:00
      }
  ]
  </code></pre>