anchor.diff:  
   // GRAMMAR OF A CLASS DECLARATION
   
  +/*
  + * alexsaveliev: replaced access_level_modifier? with class_modifiers?
  + * to handle 'public final class Foo'
  + * "Prevenging Overrides" in
  + * See https://developer.apple.com/library/mac/documentation/Swift/Conceptual/Swift_Programming_Language/Inheritance.html
  + */
   class_declaration
  - : attributes? access_level_modifier? 'class' class_name
  + : attributes? class_modifiers? 'class' class_name
      generic_parameter_clause? type_inheritance_clause? class_body
    ;
  +
  +class_modifiers
  + : access_level_modifier
  + | access_level_modifier 'final'
  + | 'final'
  + | 'final' access_level_modifier
  + ;
  +
   class_name : identifier ;
   class_body : '{' declarations? '}'  ;
   
  
positive.code: availability_argument : Platform | '*' ;
  
  /** Must match as token so Platform_version doesn't look like a float literal */
  Platform : Platform_name WS? Platform_version ;
  
  fragment
  Platform_name
  
negative.code: 
  // GRAMMAR OF AN EXTENSION DECLARATION
  
  /*
   * alexsaveliev: added requirement_clause? to support
   * "extension TypeIndexed where Value : ForwardIndexType ..."
   * see http://www.raywenderlich.com/109156/introducing-protocol-oriented-programming-in-swift-2
   */
  extension_declaration : access_level_modifier? 'extension' type_identifier requirement_clause? type_inheritance_clause? extension_body  ;
  extension_body : '{' declarations?'}'  ;
  
  // GRAMMAR OF A SUBSCRIPT DECLARATION
  