private void fillExternalAddSymbolSet(SymbolTable symbolTable, long[] symbolIDs,
			HashSet<Long> externalAddSet) {

		for (long symbolID : symbolIDs) {
			Symbol symbol = symbolTable.getSymbol(symbolID);
			if (symbol == null) {
				continue;
			}
			SymbolType symbolType = symbol.getSymbolType();
			if (symbol.isExternal() &&
				(symbolType == SymbolType.FUNCTION || symbolType == SymbolType.LABEL)) {

				externalAddSet.add(symbolID);
			}
		}
	}
Determine the type of changes to the symbols in the LATEST and MY (CheckedOut) program.
Changes can be symbol removed, added, changed, renamed, and set to primary.
@param monitor task monitor for displaying progress to the user
@throws CancelledException if the user cancels the merge.
Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/ExternalFunctionMerger.java