public Tag saveTag(User user, Tag tag) {
		Instant createdAt = now();
		if (tag.getCreatedBy() == null) {
			tag.setCreatedBy(user);
			tag.setCreatedAt(createdAt);
		}
		tag.setLastModifiedBy(user);
		tag.setLastModifiedAt(createdAt);
		return tagRepository.save(tag);
	}
Save Tag. Because this method can be called in {@link TagService} internally, so created user
/ data should be set directly.

@param user 	user
@param tag	tag
@return saved {@link Tag} instance
ngrinder-controller/src/main/java/org/ngrinder/perftest/service/TagService.java