public DBTraceDataAdapter addData(long snap, Address start, TracePlatform platform,
			DataType type, int length) throws CodeUnitInsertionException {
		DBTraceCodeManager code = trace.getCodeManager();
		return code.definedData().create(Lifespan.nowOn(snap), start, platform, type, length);
	}
Create a data unit

@param snap the starting snap
@param start the min address
@param platform the platform for data organization
@param type the data type of the unit
@param length the length, or -1 for the type's default
@return the new data unit
@throws CodeUnitInsertionException if the unit cannot be created
Ghidra/Debug/Framework-TraceModeling/src/test/java/ghidra/trace/database/ToyDBTraceBuilder.java