HoHCI-BikeSim/Assets/Scripts/SubjectManager.cs

using System;
using UnityEngine;

public class SubjectManager : MonoBehaviour
{
    public string subjectIdentifier;

    private void OnEnable()
    {
        if (string.IsNullOrEmpty(subjectIdentifier))
            throw new Exception("You have to specify a subject for the experiment!");
    }
}