LateInitializationError: el campo 'ques' no se ha inicializado

Muestra este error aunque lo he agregado tarde y requerido en el constructor de la clase Pregunta. Se muestra repetidamente

Excepción detectada por la biblioteca de widgets

Se lanzó el siguiente LateError construyendo _BodyBuilder: LateInitializationError: el campo 'ques' no se ha inicializado

Main class:

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'QuestionsAnswers.dart';
void main() {
 runApp(const Quizzler());
}
class Quizzler extends StatelessWidget {
 const Quizzler({Key? key}): super(key: key);
 @override
 Widget build(BuildContext context) {
 return MaterialApp(
 debugShowCheckedModeBanner: false,
 home: SafeArea(
 child: Scaffold(
 backgroundColor: Colors.black,
 appBar: AppBar(
 backgroundColor: Colors.grey[900],
 leading: Icon(Icons.games),
 title: Text(
 'Quizzler',
 style: TextStyle(
 fontSize: 20.0,
 fontWeight: FontWeight.bold,
 fontStyle: FontStyle.italic,
 color: Colors.white,
 ),
 ),
 ),
 body: QuizPlay(),
 ),
 ),
 );
 }
}
class QuizPlay extends StatefulWidget {
 const QuizPlay({Key? key}): super(key: key);
 @override
 State<QuizPlay> createState() => _QuizplayState();
}
class _QuizplayState extends State<QuizPlay> {
 List<Icon> score=[];// array of score icon
 List<Questions>questionsAndAnswers=[
 Questions(a:'Pakistan is an under developed country',b:true),
 Questions(a:'Imran Khan is the Prime Minister of Pakistan',b:true),
 Questions(a:'Y comes after U',b:false)
 ];
 int questiontracker=0;// variable to increment of questions
 @override
 Widget build(BuildContext context) {
 return Column(
 crossAxisAlignment: CrossAxisAlignment.stretch,
 mainAxisAlignment: MainAxisAlignment.spaceBetween,
 children: [
 Expanded(
 flex: 4,
 child: Padding(
 padding: EdgeInsets.all(10.0),
 child: Center(
 child: Text(
 questionsAndAnswers[questiontracker].ques,
 style: TextStyle(
  fontSize: 25.0,
  color: Colors.white70,
 ),
 ),
 ),
 ),
 ),
 Expanded(
 child: Padding(
 padding: EdgeInsets.all(10.0),
 child: ElevatedButton(
 style: ButtonStyle(
 backgroundColor: MaterialStateProperty.all(Colors.green),
 ),
 onPressed: () {
 //Yes button
 bool answer=questionsAndAnswers[questiontracker].ans;
 if (answer==true)
  {
  print('correct answer');
  }
 else
  {
  print('wrong answer ');
  }
 setState(() {
  questiontracker++;
  score.add(Icon(Icons.check,color: Colors.green,));
 });
 },
 child: Text(
 'Yes',
 style: TextStyle(
  fontSize: 20.0,
 ),
 ),
 ),
 ),
 ),
 Expanded(
 child: Padding(
 padding: EdgeInsets.all(10.0),
 child: ElevatedButton(
 style: ButtonStyle(
 backgroundColor: MaterialStateProperty.all(Colors.red),
 ),
 onPressed: () {
 // No button
 bool answer=questionsAndAnswers[questiontracker].ans;
 if (answer==false)
 {
  print('correct answer');
 }
 else
 {
  print('wrong answer ');
 }
 setState(() {
  questiontracker++;
  score.add(Icon(Icons.close,color: Colors.red,));
 });
 },
 child: Text(
 'No',
 style: TextStyle(
  fontSize: 20.0,
 ),
 ),
 ),
 ),
 ),
 Row(
 children: score,
 ),
 ],
 );
 }
}

###Pregunta CLASE###

class Questions{
 late String ques;
 late bool ans;
 Questions({required String a,required bool b})
 {
 a=ques;
 b=ans;
 }
}

Solución del problema

hazlo

ques = a;
ans = b;

Esto almacena el valor de la derecha en el valor de la izquierda.