}

    /**
     * Test printStackTrace functionality
     */
    public void test_printStackTrace() {
        CrawlerSystemException exception = new CrawlerSystemException("Print stack trace test");

        StringWriter stringWriter = new StringWriter();
        PrintWriter printWriter = new PrintWriter(stringWriter);
        exception.printStackTrace(printWriter);

                            threadSafeManager.addRule(rule);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    } finally {
                        endLatch.countDown();
                    }
                }
            }).start();
        }

        startLatch.countDown();

                                successCount.incrementAndGet();
                            }
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    } finally {
                        endLatch.countDown();
                    }
                }
            });
        }

        startLatch.countDown();

            numObInputDoc.set(response.getNumberOfInputDocs());
            latch.countDown();
        }).error(t -> {
            t.printStackTrace();
            latch.countDown();
            fail();
        });
        latch.await();
        assertEquals(num, numObInputDoc.get());