@Override
	public synchronized void startTransaction() {
		inTransaction = true;

		tmpAddrs = new NormalizedAddressSet(addrMap);
		tmpRegAddrs = new NormalizedAddressSet(addrMap);
		tmpChangedDataTypeIds = new HashSet<Long>();
		tmpChangedCategoryIds = new HashSet<Long>();
		tmpChangedProgramTreeIds = new HashSet<Long>();
		tmpChangedSymbolIds = new HashSet<Long>();
		tmpChangedSourceArchiveIds = new HashSet<Long>();
		tmpChangedTagIds = new HashSet<Long>();
		tmpAddedDataTypeIds = new HashSet<Long>();
		tmpAddedCategoryIds = new HashSet<Long>();
		tmpAddedProgramTreeIds = new HashSet<Long>();
		tmpAddedSymbolIds = new HashSet<Long>();
		tmpAddedSourceArchiveIds = new HashSet<Long>();
		tmpAddedTagIds = new HashSet<Long>();
	}
Construct a new ProgramChangeSet.
@param addrMap the address map.
@param numUndos the number of undo change sets to track.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramDBChangeSet.java