void CheckIsValid()
 {
     if (TextLocalisation.GetLocalisedValue(instance.key) == null)
     {
         gotKey = false;
     }
     else
     {
         gotKey = true;
     }
 }
    public override void OnInspectorGUI()
    {
        instance.GetComponent <TextMeshProUGUI>().text = (instance.preview && gotKey) ? TextLocalisation.GetLocalisedValue(instance.key) : instance.key;

        EditorGUILayout.BeginHorizontal();

        EditorGUI.BeginChangeCheck();
        instance.key = TextLocaliserEditorGUI.TextField("Localiser Key", instance.key);

        if (EditorGUI.EndChangeCheck())
        {
            CheckIsValid();
            EditorUtility.SetDirty(target);
        }

        EditorGUILayout.EndHorizontal();

        instance.preview = EditorGUILayout.Toggle("Preview?", instance.preview);
    }