///GetUserData()
 /// <summary>
 /// Retrieves UserData from PlayFab.
 /// </summary>
 /// Pre-Condition: Must be signed into a PlayFab account.
 /// Post-Condition: The Data from the PlayFab account will be retrieved.
 public static void GetUserData()
 {
     if (_playFabId == null)
         return;
     //PlayFab API call requires a request to retrieve data.
     var GetUserDataRequest = new PlayFab.ClientModels.GetUserDataRequest(){ PlayFabId = _playFabId };
     //PlayFab API call to retrieve data from the PlayFab account.
     PlayFabClientAPI.GetUserData(GetUserDataRequest,
         (result) =>
         {
             Debug.Log(_playFabId + "GetUserDataRequest");
             foreach (var entry in result.Data)
             {
                 Debug.Log(entry.Key + ": " + entry.Value.Value);
                 //This will be used for Clear Data.
                 _Key.Add(entry.Key);
             }
             DataResult.Invoke(result);
         },
         (error) =>
         {
             Debug.Log(_playFabId);
             Debug.Log("Error: GetUserData()");
             Debug.Log(error.ErrorMessage);
         }
     );
 }