anchor.diff:     * Checks if the given name is a key for any of the Class Maps.
      */
     bool containsKey(String name) {
  -    return abstractClasses.containsKey(name) ||
  -        regularClasses.containsKey(name) ||
  -        errors.containsKey(name);
  -  }
  -
  +    return classes.containsKey(name) || errors.containsKey(name);
  +  }
  +
  +  /**
  +   * Creates a [Map] with [Class] names and a preview comment.
  +   */
  +  Map classMap(Class clazz) {
  +    var finalMap = { 'name' : clazz.qualifiedName };
  +    if (clazz.comment != '') {
  +      var index = clazz.comment.indexOf('</p>');
  +      finalMap['preview'] = '${clazz.comment.substring(0, index)}</p>';
  +    }
  +    return finalMap;
  +  }
  +  
     Map toMap() => {
  -    'abstract': abstractClasses.values.where(_isVisible)
  -      .map((e) => e.qualifiedName).toList(),
  -    'class': regularClasses.values.where(_isVisible)
  -      .map((e) => e.qualifiedName).toList(),
  +    'class': classes.values.where(_isVisible)
  +      .map((e) => classMap(e)).toList(),
       'typedef': recurseMap(typedefs),
       'error': errors.values.where(_isVisible)
  -      .map((e) => e.qualifiedName).toList()
  +      .map((e) => classMap(e)).toList()
     };
   }
   
  
positive.code: 
      clazz.ensureComments();
  
      if (isError(mirror.qualifiedName)) {
        errors[mirror.simpleName] = clazz;
      } else if (mirror.isTypedef) {
        if (_includePrivate || !mirror.isPrivate) {
  
negative.code:   return outputMap;
  }
  
  /**
   * A class representing all programming constructs, like library or class.
   */
  