// checkQuestionForDuplicateLabels checks if there are multiple questions with the same label, and if so, adds an warning to the typechecker
func checkQuestionForDuplicateLabels(question interfaces.Question, typeChecker interfaces.TypeChecker) {
	labelKnown := typeChecker.IsLabelUsed(question.Label())

	if labelKnown {
		typeChecker.AddEncounteredWarning(errors.NewDuplicateLabelWarning(question, typeChecker.VarIDForLabel(question.Label())))
		return
	}

	typeChecker.MarkLabelAsUsed(question.Label(), question.VarDecl())
}