title: How to obtain typeface for RobotoTextView from reference styleable attribute
body: <p>I have a custom view which contains several RobotoTextViews and I want to set typefaces for them.
  So, I use declare-styleable item like this:  </p>
  
  <pre><code>&lt;declare-styleable name="CustomView"&gt;
          &lt;attr name="firstTextviewStyle" format="reference" /&gt;
          &lt;attr name="secondTextviewStyle" format="reference" /&gt;
  &lt;/declare-styleable&gt;
  </code></pre>
  
  <p>The attributes are referenced to styles. </p>
  
  <pre><code>&lt;style name="firstTextAppearance"&gt;
          &lt;item name="typeface"&gt;roboto_medium&lt;/item&gt;
          &lt;item name="android:textSize"&gt;16sp&lt;/item&gt;
          &lt;item name="android:textColor"&gt;@android:color/white&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>So, question is, how to get typeface attr value from this?</p>