StaggeredTile.extent constructor
Creates a StaggeredTile with the given crossAxisCellCount and mainAxisExtent.
This tile will have a fixed main axis extent.
Implementation
const StaggeredTile.extent(this.crossAxisCellCount, this.mainAxisExtent)
: assert(crossAxisCellCount >= 0),
assert(mainAxisExtent != null && mainAxisExtent >= 0),
mainAxisCellCount = null;