src/vs/workbench/contrib/debug/browser/debugService.ts/DebugService/addWatchExpression
class DebugService:	addWatchExpression(name?: string): void {
		const we = this.model.addWatchExpression(name);
		if (!name) {
			this.viewModel.setSelectedExpression(we);
		}
		this.debugStorage.storeWatchExpressions(this.model.getWatchExpressions());
	}