try {
            helper.completeOperation("nonexistent_operation");
        } catch (final Exception e) {
            fail("completeOperation should not throw: " + e.getMessage());
        }
    }

    @Test
    public void test_completeOperation_doubleCall_safe() {
        // Calling completeOperation twice must not throw (idempotent release)

                        coordinator.completeOperation("clear_crawler_index");
                    }, e -> {
                        logger.warn("Failed to delete .crawler.* indices.", e);
                        coordinator.completeOperation("clear_crawler_index");
                    }));
        } catch (final Exception e) {
            coordinator.completeOperation("clear_crawler_index");
            throw e;
        }

     * Safe to call multiple times; does nothing if the document is already deleted.
     *
     * @param operationName the operation name whose lock should be released.
     */
    public void completeOperation(final String operationName) {
        try (CurlResponse getResponse = ComponentUtil.getCurlHelper() //
                .get("/" + getIndexName() + "/_doc/" + operationName) //
                .execute()) {