How to make the list view builder size to minimum

• I'm using list view builder inside a flexible widget with fit:FlexFit.loose but it occupying all the available space below, my requirement is, that list view builder need to take the minimun space(required space) if there are less items.
• I tried with below code

Dart pad Reference

Code :

import 'package:flutter/material.dart';
import 'dart:math';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  Random random = new Random();

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Column(children: [
            Padding(
                padding: EdgeInsets.all(15.0),
                child:
                    Text('List View Builder', style: TextStyle(fontSize: 20))),
            Flexible(
                fit: FlexFit.loose,
                child: ListView.builder(
                  itemBuilder: (BuildContext context, int index) {
                    return Container(
                        color: Color(random.nextInt(0xffffffff)), height: 30);
                  },
                  itemCount: 3,
                )),
            Padding(
              padding: EdgeInsets.all(15.0),
              child: RaisedButton(
                  onPressed: () {},
                  child:
                      Text('Collected Amount', style: TextStyle(fontSize: 20))),
            )
          ]),
        ),
      ),
    );
  }
}

I founded a solution for this, use shrinkWrap: true in List view builder, it will make the list view builder to minimum size.

 ListView.builder(
          shrinkWrap: true,
          itemBuilder: (BuildContext context, int index) {
           return requiredWidget;
          }