public VTMatchTagDB getOrCreateMatchTagDB(VTMatchTag tag) {
		if (tag == null) {
			return null; // can't create or locate
		}

		if (tag == VTMatchTag.UNTAGGED) {
			return null; // no DB item for the untagged state
		}

		String tagName = tag.getName();
		return createMatchTag(tagName);
	}
Mark the state of a Version Tracking item as having changed and generate
the event of the specified type.  Any or all parameters may be null.
@param eventType event type
@param affected the version tracking object that was affected by the change.
@param oldValue original value or an Object that is related to the event.
@param newValue new value or an Object that is related to the event.
Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/VTSessionDB.java