sclass ModifiedWebRequest implements IWebRequest {
  IWebRequest originalRequest;
  // any non-null field will override original value
  S uri;
  SS params;
  SS headers;
  SS files;
  S cookie;
  
  *(IWebRequest *originalRequest) {}

  public S uri() { ret uri != null ? uri : originalRequest.uri(); }
  public SS params() { ret params != null ? params : originalRequest.params(); }
  public SS headers() { ret headers != null ? headers : originalRequest.headers(); }
  public SS files() { ret files != null ? files : originalRequest.files(); }
  public S cookie() { ret cookie != null ? cookie : originalRequest.cookie(); }
  public bool isHttps() { ret originalRequest.isHttps(); }
}

Began life as a copy of #1028677