Spacer
This widget motivated by Spacer in Flutter.
Spacer creates an adjustable, empty spacer that can be used to tune the spacing between widgets in a Flex container, like Row or Column.
The Spacer widget will take up any available space, so setting the Flex.mainAxisAlignment on a flex container that contains a Spacer to MainAxisAlignment.spaceAround, MainAxisAlignment.spaceBetween, or MainAxisAlignment.spaceEvenly will not have any visible effect: the Spacer has taken up all of the additional space, therefore there is none left to redistribute.
See: https://api.flutter.dev/flutter/widgets/Spacer-class.html
Props
flex
Value: number (default: 1)