@Override
            public void run() {
                try {
                    evictExpired();
                } catch (Exception e) {
                    LOGGER.error("Error running entry eviction timerTask: {}", e.getMessage(), e);
                }
            }
@return An optional containing a non-blank attribute value, else empty.
stroom-receive/stroom-receive-common/src/main/java/stroom/receive/common/DataFeedKeyServiceImpl.java