Align the child within the container.
If non-null, the container will expand to fill its parent and position its child within itself according to the given value. If the incoming constraints are unbounded, then the child will be shrink-wrapped instead.
Ignored if child is null.
- Alignment, a class with convenient constants typically used to specify an AlignmentGeometry.
- AlignmentDirectional, like Alignment for specifying alignments relative to text direction.
final AlignmentGeometry? alignment;