anchor.diff:    }
   
     /**
  -   * Return the documentation comment associated with this node, or `null` if this node does
  -   * not have a documentation comment associated with it.
  -   *
  -   * @return the documentation comment associated with this node
  +   * Return the documentation comment associated with this node, or `null` if
  +   * this node does not have a documentation comment associated with it.
      */
     Comment get documentationComment => _comment;
   
     /**
  -   * Set the documentation comment associated with this node to the given comment.
  -   *
  -   * @param comment the documentation comment to be associated with this node
  +   * Set the documentation comment associated with this node to the given
  +   * [comment].
      */
     void set documentationComment(Comment comment) {
       _comment = becomeParentOf(comment);
  
positive.code:   Token get endToken => _shownNames.endToken;
  
    /**
     * Return the list of names from the library that are made visible by this combinator.
     *
     * @return the list of names from the library that are made visible by this combinator
     */
    NodeList<SimpleIdentifier> get shownNames => _shownNames;
  
  
negative.code: 
    @override
    void visitChildren(AstVisitor visitor) {
      _safelyVisitChild(_block, visitor);
    }
  }
  
  /**
   * A boolean literal expression.
   *
   * > booleanLiteral ::=
   * >     'false' | 'true'
   */
  class BooleanLiteral extends Literal {
    /**
  