code: protected String doRequest(HttpRequestBase request) throws IOException {
          for (Map.Entry<Header, String> header : headers.entrySet()) {
              request.setHeader("X-RallyIntegration" + header.getKey().name(), header.getValue());
          }
  
          return this.executeRequest(request);
      }
docs: Execute a request against the WSAPI
  
  @param request the request to be executed
  @return the JSON encoded string response
  @throws IOException if a non-200 response code is returned or if some other
  problem occurs while executing the request