DataType getDataType(UniversalID sourceID, UniversalID dataTypeID) {
			if (sourceID == null || sourceID.equals(universalID)) {
				sourceID = LOCAL_ARCHIVE_UNIVERSAL_ID;
			}

			Map<UniversalID, DataType> idMap =
				map.computeIfAbsent(sourceID, k -> new ConcurrentHashMap<>());
			UniversalID sourceArchiveID = sourceID;

			// note: this call is atomic and has a lock on the 'idMap'.  It may call to a method
			//       that requires a db lock.  As such, the call to computeIfAbsent() must be 
			//       made while holding the db lock.
			return idMap.computeIfAbsent(dataTypeID,
				k -> findDataTypeForIDs(sourceArchiveID, dataTypeID));
		}
{@code IdsToDataTypeMap} - DataType resolve cache map
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java