title: How to obtain a theme by its reference id
body: <p>I need to extract a default value from a theme, BUT NOT from the current theme.</p>
  
  <p>I know that I can get get the attributes from the current theme like this:</p>
  
  <pre><code>TypedValue typedValue = new TypedValue();
  Theme currentTheme = context.getTheme();
  currentTheme.resolveAttribute(android.R.attr.windowBackground, typedValue, true);
  // result is in: typedValue.data
  </code></pre>
  
  <p>but I need something like:</p>
  
  <pre><code>Theme darkTheme = getTheme(R.style.AppTheme.Dark);
  </code></pre>
  
  <p>...
  I only need to extract a single value, I do not want to change the current theme.</p>