title: Happymapper(fork) - output from multiple classes
body: <p>My question relates to creating output based on the documentation at <a href="https://github.com/dam5s/happymapper">https://github.com/dam5s/happymapper</a> which is the fork of happymapper using nokogiri.</p>
  
  <p>I have used 2 examples in toying with documentation. This is my example.</p>
  
  <pre><code>xml_doc = &lt;&lt;EOF
  &lt;address location='home'&gt;
    &lt;street&gt;Milchstrasse&lt;/street&gt;
    &lt;street&gt;Another Street&lt;/street&gt;
    &lt;housenumber&gt;23&lt;/housenumber&gt;
    &lt;postcode&gt;26131&lt;/postcode&gt;
    &lt;city&gt;Oldenburg&lt;/city&gt;
    &lt;country code="de"&gt;Germany&lt;/country&gt;
  &lt;/address&gt;
  EOF
  
  class Address
    include HappyMapper
  
    tag 'address'
  
    element :housenumber, Integer, :tag =&gt; "housenumber"
  end
  
  class Country
    include HappyMapper
  
    tag 'country'
  
    attribute :code, String
    content :name, String
  
  end
  
  outputs = Country.parse(xml_doc)
  outputs.each do |output|
    puts output.code
    puts output.name
    puts output.housenumber
  end
  </code></pre>
  
  <p><strong>Expected output</strong></p>
  
  <pre><code>de
  Germany
  23
  </code></pre>
  
  <p>My output</p>
  
  <pre><code>sayth@sayth-E6410 ~/race (master●)$ ruby read_race.rb            [ruby-2.4.0p0]
  de
  Germany
  read_race.rb:49:in `block in &lt;main&gt;': undefined method `housenumber' for #&lt;Country:0x0055e55facf798 @code="de", @name="Germany"&gt; (NoMethodError)
      from read_race.rb:46:in `each'
      from read_race.rb:46:in `&lt;main&gt;'
  </code></pre>