code: @Override
      protected String doRequest(HttpRequestBase request) throws IOException {
          request.setHeader(API_KEY_HEADER, this.apiKey);
          return super.doRequest(request);
      }
docs: Execute a request against the WSAPI
  
  @param request the request to be executed
  @return the JSON encoded string response
  @throws java.io.IOException if a non-200 response code is returned or if some other
  problem occurs while executing the request