code: public long getContentLength() {
          try {
              return getInternalResponse().body().contentLength();
          } catch (NullPointerException e){
              logger.error("Failed to get the response content length from " + getRequestURL() + ". Error: " + e.getMessage());
              return 0;
          }
      }
docs: This method gets the Content-Length of the response body.
  
  @return The content length of the response.