Does Flutter support negative margin?

Negative margin is generally not needed but there are situations where it’s really useful. For example: why use negative margins?

For now, when I set margin for a container to a negative value, I got the following error:

I/flutter ( 3173): 'package:flutter/src/widgets/container.dart': Failed assertion: line 251: 'margin == null ||
I/flutter ( 3173): margin.isNonNegative': is not true.

The container has a useful transform property.

child: Container(
  color: Theme.of(context).accentColor,
  transform: Matrix4.translationValues(0.0, -50.0, 0.0),
),

I'm gonna give an answer for this, mostly because I had to find a way to do this.

I would like to say that it is not ideal and could likely be accomplished in a better way, but it does give the desired effect.

As you can see, the text can be pulled negatively outside its parent using a stack:

Container(
  constraints: BoxConstraints.loose(Size.fromHeight(60.0)),
  decoration: BoxDecoration(color: Colors.black), 
  child: 
    Stack(
      alignment: Alignment.topCenter,
      overflow: Overflow.visible,
      children: [
        Positioned(
          top: 10.0,
          left: -15.0,
          right: -15.0,
          child: Text("OUTSIDE CONTAINER", style: TextStyle(color: Colors.red, fontSize: 24.0),)
        )
      ]
    )
)