code: public CompareToBuilder append(final Object lhs, final Object rhs) {
          return append(lhs, rhs, null);
      }
docs: <p>Appends to the <code>builder</code> the comparison of
  two <code>Object</code>s.</p>
  
  <ol>
  <li>Check if <code>lhs == rhs</code></li>
  <li>Check if either <code>lhs</code> or <code>rhs</code> is <code>null</code>,
  a <code>null</code> object is less than a non-<code>null</code> object</li>
  <li>Check the object contents</li>
  </ol>
  
  <p><code>lhs</code> must either be an array or implement {@link Comparable}.</p>
  
  @param lhs  left-hand object
  @param rhs  right-hand object
  @return this - used to chain append calls
  @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
  with <code>lhs</code>