@Override
    @SuppressWarnings("unchecked")
    public <T> T getTtlAttachment(@NonNull String key) {
        return (T) attachments.get(key);
    }
{@link TtlAttachments} delegate/implementation.

@author Jerry Lee (oldratlee at gmail dot com)
@see com.alibaba.ttl3.TtlRunnable
@see com.alibaba.ttl3.TtlCallable
ttl-core/src/main/java/com/alibaba/ttl3/spi/TtlAttachmentsDelegate.java