private List<Long> getDeletes(long[] ids, FunctionTagManager tagManager,
			FunctionTagManager originalTagManager) {
		List<Long> retList = new ArrayList<>();

		for (long id : ids) {
			FunctionTag tag = tagManager.getFunctionTag(id);
			FunctionTag originalTag = originalTagManager.getFunctionTag(id);

			if (tag == null && originalTag != null) {
				retList.add(id);
			}
		}
		return retList;
	}
Given a list of tag IDs, returns the subset of those who's tags have
been deleted.

A delete is identified by comparing the given program version against
Original; if the tag exists in the latter but not the former, it was
deleted.

@param ids the full list of ids to check
@param tagManager the source program tag manager
@param originalTagManager the Original program tag manager

@return
Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/FunctionTagMerger.java