code: public void validate(Object response) throws RedditParseException {
          
          // Check for null
          if (response == null) {
              throw new RedditParseException();
          }
          
          // Check it is a JSON response
          if (!(response instanceof JSONObject)) {
              throw new RedditParseException("not a JSON response");
          }
          
          // Cast to JSON object
          JSONObject jsonResponse = ((JSONObject) response);
          
          // Check for error
          if (jsonResponse.get("error") != null) {
              throw new RedditParseException(JsonUtils.safeJsonToInteger(jsonResponse.get("error")));
          }
          
          // Check that data exists
          if (jsonResponse.get("data") == null && jsonResponse.get("json") == null) {
              throw new RedditParseException("data is missing from listing");
          }
          
      }
docs: Validate that it is indeed the starting of a listing of reddit things.
  
  @param response Object returned by JSON parser
  
  @throws RedditRequestException If the response is not valid listing of reddit things