title: Duplicate class error on Puppet Enterprise Hiera config
body: <p>I'm getting the following error while running <code>puppet agent -t</code> </p>
  
  <pre><code>Duplicate declaration: Class[MyModule] is already declared; cannot redeclare on node mynode.mydomain.com
  </code></pre>
  
  <p>I'm using heira as my approach. In mynode.mydomain.com.yaml I have the following</p>
  
  <pre><code>classes:
    - MyModule:elasticsearch
  
  mtd::elasticsearch::install_dir: /opt/es
  mtd::elasticsearch::version: 1.5.1
  mtd::elasticsearch::master_node: true
  mtd::elasticsearch::data_node: true
  mtd::elasticsearch::cluster: elasticsearch
  </code></pre>