private List<DBRecord> getHistoryRecords(Address addr, CommentType commentType)
			throws IOException {
		RecordIterator it = historyAdapter.getRecordsByAddress(addr);
		List<DBRecord> list = new ArrayList<>();
		while (it.hasNext()) {
			DBRecord rec = it.next();
			if (rec.getByteValue(CommentHistoryAdapter.HISTORY_TYPE_COL) == commentType.ordinal()) {
				list.add(rec);
			}
		}
		return list;
	}
Get the comment history for the comment type at the given address 

@param addr address for the comment history
@param commentType comment type
@return zero length array if no history exists
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CodeManager.java