@Override
	public Iterator<LabelHistory> getLabelHistory() {
		try {
			return new LabelHistoryIterator(historyAdapter.getAllRecords());
		}
		catch (IOException e) {
			program.dbError(e);
		}
		return new LabelHistoryIterator(new EmptyRecordIterator());
	}
Returns the next available external symbol address

@return the address
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/symbol/SymbolManager.java