Flutter reduce space between widgets

I try to display a ExpansionTile with some text in it followed by an Image. Referring to the screenshot you can see that there is some space between both widgets. Does someone know how I can reduce this space?

class Test extends StatelessWidget {
  const Test({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        backgroundColor: backGround,
        appBar: AppBar(
          title: const Text('Aromatics'),
          backgroundColor: appbarColor,
        ),
        body: Column(
          children: [
            ExpansionTile(
                iconColor: titleColor,
                title: const Text('Tst', style: TextStyle(color: titleColor)),
                subtitle: const Text('Test subtitle',
                    style: TextStyle(color: Colors.white)),
                children: [
                  Container(
                    margin: const EdgeInsets.only(left: 20),
                    child: Column(
                      children: const [
                        Text('Test text',
                            style:
                                TextStyle(color: Colors.white, fontSize: 13)),
                      ],
                    ),
                  ),
                ]),
            const SizedBox(
              height: 1,
            ),
            Expanded(
              child: Image.asset('assets/images/test.webp'),
            ),
          ],
        ));
  }
}

>Solution :

As per the ExpansionTile Doc, you can use childrenPadding to manage the padding for the children widget

Specifies padding for children.
If this property is null then ExpansionTileThemeData.childrenPadding is used. If that is also null then the value of childrenPadding is EdgeInsets.zero.