SliverFixedExtentList constructor

const SliverFixedExtentList({Key key, @required SliverChildDelegate delegate, @required double itemExtent })

Creates a sliver that places box children with the same main axis extent in a linear array.

Implementation 

const SliverFixedExtentList({
  Key key,
  @required SliverChildDelegate delegate,
  @required this.itemExtent,
}) : super(key: key, delegate: delegate);