anchor.diff:  }
   
   /**
  - * A `KeywordToken` is a keyword in the language.
  + * A token representing a keyword in the language.
    */
   class KeywordToken extends Token {
     /**
  
positive.code: }
  
  /**
   * A `SyntheticStringToken` is a token whose value is independent of it's type.
   */
  class SyntheticStringToken extends StringToken {
    /**
  
negative.code: import 'source.dart';
  
  /**
   * The opening half of a grouping pair of tokens. This is used for curly
   * brackets ('{'), parentheses ('('), and square brackets ('[').
   */
  class BeginToken extends Token {
    /**
  