#vulnerable code 
                                private String createTemporaryEphemeralFileStore() {

        try {
            System.out.format("java tmpdir root: %s\n", System.getProperty("java.io.tmpdir"));

            Path path = Files.createTempDirectory("neo4j.db");
            System.out.format("Check temporary directory %s\n", path.toString());

            File f = path.toFile();
            System.out.format("Checking directory actually exists as a file %s\n", f.exists());

            f.deleteOnExit();
            URI uri = f.toURI();

            System.out.format("Checking URI object is not null: %s\n", uri != null);
            System.out.format("Checking URI as String %s\n", uri.toString());

            String fileStoreUri = uri.toString();

            return fileStoreUri;
        } catch (Exception e) {
            System.out.println("Caught an exception:");
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    } 
                            #location 16 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private String createTemporaryEphemeralFileStore() {

        try {
            Path path = Files.createTempDirectory("neo4j.db");
            File f = path.toFile();
            f.deleteOnExit();
            URI uri = f.toURI();
            String fileStoreUri = uri.toString();
            return fileStoreUri;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }