#vulnerable code 
                                private boolean initGhRepository() {
        GitHub gitHub = null;
        try {
            GhprbGitHub repo = helper.getGitHub();
            if (repo == null) {
                return false;
            }
            gitHub = repo.get();
            if (gitHub.getRateLimit().remaining == 0) {
                return false;
            }
        } catch (FileNotFoundException ex) {
            logger.log(Level.INFO, "Rate limit API not found.");
        } catch (IOException ex) {
            logger.log(Level.SEVERE, "Error while accessing rate limit API", ex);
            return false;
        }

        if (ghRepository == null) {
            try {
                ghRepository = gitHub.getRepository(reponame);
            } catch (IOException ex) {
                logger.log(Level.SEVERE, "Could not retrieve GitHub repository named " + reponame + " (Do you have properly set 'GitHub project' field in job configuration?)", ex);
                return false;
            }
        }
        return true;
    } 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private boolean initGhRepository() {
        GitHub gitHub = null;
        try {
            GhprbGitHub repo = helper.getGitHub();
            if (repo == null) {
                return false;
            }
            gitHub = repo.get();
            if (gitHub == null) {
                logger.log(Level.SEVERE, "No connection returned to GitHub server!");
                return false;
            }
            if (gitHub.getRateLimit().remaining == 0) {
                return false;
            }
        } catch (FileNotFoundException ex) {
            logger.log(Level.INFO, "Rate limit API not found.");
        } catch (IOException ex) {
            logger.log(Level.SEVERE, "Error while accessing rate limit API", ex);
            return false;
        }

        if (ghRepository == null) {
            try {
                ghRepository = gitHub.getRepository(reponame);
            } catch (IOException ex) {
                logger.log(Level.SEVERE, "Could not retrieve GitHub repository named " + reponame + " (Do you have properly set 'GitHub project' field in job configuration?)", ex);
                return false;
            }
        }
        return true;
    }