title: Class instance variables not inherited "activerecord-import" rails
body: <p>I'm using <code>activerecord-import (1.0.3)</code>.
  There is a way to override the <code>sequence_name</code> of a model in order to have import taking it into account:</p>
  <pre class="lang-rb prettyprint-override"><code>class A &lt; ApplicationRecord
    self.abstract_class = true
    self.sequence_name = &quot;my_new_seq&quot;
  end
  </code></pre>
  <p>However when I do:</p>
  <pre class="lang-rb prettyprint-override"><code>class B &lt; A
    ...
  end
  
  B.import! data # it uses B default sequence_name
  </code></pre>
  <p>The way to get the right <code>sequence_name</code> used is to specify it once again:</p>
  <pre><code>class B &lt; A
    self.sequence_name = &quot;my_new_seq&quot;
  end
  
  B.import! data # uses B good sequence_name
  </code></pre>
  <p>How can I get this value to be passed to subclasses?</p>
  <h2>Response</h2>
  <p>Class A is an abstract class. sequence_name should be defined the following way:</p>
  <pre class="lang-rb prettyprint-override"><code>class A &lt; ApplicationRecord
    self.abstract_class = true
    
    class &lt;&lt; self
      def sequence_name
        &quot;my_new_seq&quot;
      end
    end
   
  end
  </code></pre>