private void handleSymbolRenamed(ProgramChangeRecord r) {
		Symbol symbol = (Symbol) r.getObject();
		if (!(symbol instanceof FunctionSymbol)) {
			return;
		}

		FunctionSymbol functionSymbol = (FunctionSymbol) symbol;
		Function function = (Function) functionSymbol.getObject();
		if (updateRootNodes(function)) {
			return; // the entire tree will be rebuilt
		}

		incomingTree.runTask(new UpdateFunctionNodeTask(incomingTree, function));
		outgoingTree.runTask(new UpdateFunctionNodeTask(outgoingTree, function));
	}
A variable used to restrict open-ended operations, like expanding all nodes or filtering.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/calltree/CallTreeProvider.java