ClampOverscrolls({Key key, ScrollableEdge edge: ScrollableEdge.none, @required Widget child })

Creates a widget that controls whether viewport descendants will overscroll their contents.

The edge and child arguments must not be null.

Source 

ClampOverscrolls({
  Key key,
  this.edge: ScrollableEdge.none,
  @required Widget child,
}) : super(key: key, child: child) {
  assert(edge != null);
  assert(child != null);
}