anchor.diff:  /**
    * The function type of a plugin.
    */
  -typedef Future Extension(dynamic pluggable);
  +typedef dynamic Extension(dynamic pluggable);
   
   
   /**
  
positive.code:   /**
     * The instance being extended, will be passed to all extensions.
     */
    final dynamic pluggable;
  
    /**
     * The list of futures that this loader will wait on.
  
negative.code:   /**
     * Create a new extension loader for the given pluggable.
     */
    Extensible([this._pluggable]);
  
    /**
     * The argument passed during plugin setup.
     *
     * Either passed on instantiation, or will be this,
     */
    dynamic get pluggable => _pluggable != null ? _pluggable : this;
  
    /**
     * Load an extension.
     */
    dynamic extend(Extension plugin) {
      var result = plugin(pluggable);
      if (result is Future) {
        waitingFor.add(result);
      }
      return result;
    }
  
    /**
  