@Override
	public Data next() {
		if (hasNext()) {
			Data ret = nextData;
			nextData = null;
			return ret;
		}
		return null;
	}
@see ghidra.program.model.listing.DataIterator#next()
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/DataFilteredCodeUnitIterator.java