runSpacing property
final
How much space to place between the runs themselves in the cross axis.
For example, if runSpacing is 10.0, the runs will be spaced at least 10.0 logical pixels apart in the cross axis.
If there is additional free space in the overall Wrap (e.g., because the wrap has a minimum size that is not filled), the additional free space will be allocated according to the runAlignment.
Defaults to 0.0.
Implementation
final double runSpacing;