public void test_get_nullProperty() {
        // Test getting non-existent property
        try {
            fessConfig.get("non.existent.property");
            fail("Should throw exception for non-existent property");
        } catch (ConfigPropertyNotFoundException e) {
            // Expected exception
            assertTrue(e.getMessage().contains("non.existent.property"));
        }
    }

        // Test with property that doesn't exist and default value
        cmdList.clear();
        execJob.testAddSystemProperty(cmdList, "non.existent.property", "default.value", null);
        assertEquals(1, cmdList.size());
        assertEquals("-Dnon.existent.property=default.value", cmdList.get(0));

        // Test with property that doesn't exist and no default value
        cmdList.clear();

            // Expected - file no longer exists
        }
    }

    @Test
    public void testFileBasedCacheCloseNonExistentFile() {
        tempFile = new File(Curl.tmpDir, "non-existent-file.tmp");
        assertFalse(tempFile.exists());

        ContentCache cache = new ContentCache(tempFile);

        // Should throw IOException when file doesn't exist
        try {
            cache.close();

        emptyDir.mkdirs();
        assertTrue(emptyDir.exists());

        // Simulate the behavior of postVisitDirectory - delete empty directories
        if (emptyDir.isDirectory() && emptyDir.list().length == 0) {
            emptyDir.delete();
        }

        assertFalse(emptyDir.exists());
    }

    // Test FilePurgeVisitor postVisitDirectoryWithException

                errorMessage.set("SetException call exited before future was complete.");
              }
            }
          });
      executor.execute(
          new Runnable() {
            @Override
            public void run() {
              future.cancel(true);
              if (!future.isDone()) {
                errorMessage.set("Cancel call exited before future was complete.");
              }

        Files.createDirectory(existingDir);
        Files.createFile(existingDir.resolve("test.txt"));

        assertTrue(Files.exists(existingDir));
        themeHelper.closeQuietly(existingDir);
        // Directory should be deleted
        assertFalse(Files.exists(existingDir));
    }

    public void test_closeQuietly_nestedDirectory() throws IOException {

        assertEquals(123, dataStoreParams.get("key2"));

        dataStoreParams.put("key3", null);
        assertNull(dataStoreParams.get("key3"));
    }

    // Test get for non-existent key
    public void test_getNonExistentKey() {
        assertNull(dataStoreParams.get("nonexistent"));
    }

    // Test getAsString with String value
    public void test_getAsStringWithStringValue() {

        assertTrue(permissionDenied.getMessage().contains("Permission denied"));

        // Scenario 4: Exit code error
        CommandExecutionException exitCodeError = new CommandExecutionException("Command exited with non-zero code: 127");
        assertTrue(exitCodeError.getMessage().contains("non-zero code"));
    }

   * CacheBuilder#expireAfterWrite} or {@link CacheBuilder#expireAfterAccess}.
   */
  EXPIRED {
    @Override
    boolean wasEvicted() {
      return true;
    }
  },

  /**
   * The entry was evicted due to size constraints. This can occur when using {@link
   * CacheBuilder#maximumSize} or {@link CacheBuilder#maximumWeight}.
   */
  SIZE {
    @Override
    boolean wasEvicted() {
      return true;
    }
  };

            if (invalidCertFile != null && invalidCertFile.exists()) {
                invalidCertFile.delete();
            }
        }
    }

    public void test_init_withNonExistentSSLCertificate() {
        setupMockConfig("localhost:9200", "", "", "/non/existent/cert.crt");

        curlHelper.init();

        // Should handle non-existent certificate gracefully